Sold out 3 times already this year. Check if the CO detectors are still in stock.
Demand has been overwhelming. They had to be restocked twice already and there is no guarantee on how long this batch will last. Check availability below before it’s gone again.
Live inventory · Updated in real time
units left in this batch
Ships today if ordered before 5 PM · Next restock: mid-October
Sell-out risk
High
Next restock
Mid-Oct
Last sold out
Sep 14, 2026
Every cold snap empties our warehouse faster. If it’s available right now, don’t wait for the first freeze to decide.
Stock numbers reflect units available to ship today and update as orders are placed.
Most people who land here will close this tab.
Not because they don’t care. Because they tell themselves they’ll come back later.
Later is exactly when it’s too late.
Carbon monoxide doesn’t wait until you’re ready. It fills the house on an ordinary night, while the people you love are asleep.
This is the detector you just saw.
Sentivo Detector™. It shows the actual carbon monoxide level in your home, live, starting from 0 PPM. Not a green light that stays quiet for hours. It also catches natural gas and propane leaks. Plugs into any outlet in 30 seconds. No tools. No electrician. Battery backup if the power goes out. Works the night you plug it in.
One on every floor, and one outside the bedrooms. That’s the recommendation.
Every year, more than 100,000 Americans are rushed to the ER with carbon monoxide poisoning. Hundreds of them die.
Most of it happens at home. And none of them noticed anything until it was already too late.
You’ve seen the headlines. Every winter it’s the same story, in a different town every week: a family found unconscious in their own home. A couple who never woke up. Kids rushed to the hospital hours after the furnace kicked on.
And it always starts when the cold hits. More than half of all CO poisonings happen between November and February. (CDC) That season starts again in a few weeks.
They didn’t see it. They didn’t smell it. Nobody in the house knew anything was wrong.
If your home has anything that burns fuel (a furnace, a water heater, a gas stove, a fireplace, a car in the attached garage), the only thing standing between your family and the silent killer is whether someone notices in time.
Most CO poisonings happen at home, in houses just like this one.
“People who are sleeping can die from CO poisoning before they ever have symptoms.”
— U.S. Centers for Disease Control and Prevention
No headache to wake them. No dizziness to warn them. No second chance. Just a quiet house, and an alarm on the ceiling that is still waiting.
Why this matters right now
The deadliest months of the year are about to start
You are here
Sep
Oct
Nov
Peak
Dec
Jan
Feb
Mar
Apr
Heating season
Highest CO poisoning rates
>50%
of all CO poisonings happen November–February. (CDC)
#1
non-medical poison killer in the U.S. (CDC)
14,000+
are hospitalized from it every year. (CDC)
The #1 source of CO in American homes? Heating systems that aren’t working right. The same furnace that’s been sitting untouched in your basement all summer, about to run every night for the next five months.
Why every winter looks the same for first responders
Don’t go into CO season blind
See how thousands of families are checking the air in their homes before the first cold night.
★★★★★ 4.8 from 2,127 families · 100-night guarantee
“But I already have a CO alarm.”
That’s what almost every family says. And it’s exactly why they feel safe when they shouldn’t. Because almost nobody knows what that alarm is actually built to do.
Almost every CO alarm sold in the U.S. is tested to a standard called UL 2034. And that standard requires your alarm to wait.
4 hrs
of allowed silence
At 30 PPM: required to stay completely silent
At 70 PPM: not allowed to sound for the first hour, and can wait up to 4
No number. No early warning. Just a green light.
Read that again. Your family can be breathing CO for hours while a perfectly working alarm says nothing. That’s not a defect. That’s the design.
And when did you last check yours? Most alarms have a sensor that expires after 5–7 years. The test button checks the beep. It doesn’t tell you whether the sensor can still detect anything.
A quiet alarm doesn’t mean safe air. It means you don’t know.
It hits the people you love first
Your kids
Children under 10 have the highest rate of CO emergency room visits of any age group. (CDC)
Your parents
Older adults and people with heart conditions are more likely to become seriously ill.
A baby on the way
CO exposure is especially dangerous for unborn babies. (Mayo Clinic)
And the early signs? Headache. Nausea. Tiredness. The exact same symptoms as the winter flu that’s going around. Which is why so many families never realize what’s happening until someone doesn’t wake up feeling right.
Families who saw it before it was too late
23 PPM★★★★★
“Week one, I see 23 PPM in the basement. My $40 alarm upstairs? Quiet as always. Cracked heat exchanger on a 9-year-old furnace.”
Marcus D. · Des Moines, IA
12 PPM★★★★★
“The gas dryer vent had come loose behind the wall. No symptoms yet, no beeping alarm. Just a number telling us something was wrong.”
Andrea L. · Madison, WI
0 PPM★★★★★
“My dad is 78 and lives alone. Every Sunday I ask what the number says. Zero every time. It’s the only way I sleep.”
Sarah K. · Pittsburgh, PA
Answer these 3 questions before bed tonight
1
Do you have a gas furnace, water heater, stove, fireplace or attached garage?
2
Do you know how old the sensor in your CO alarm is?
3
Could you tell me, right now, what the CO level in your home is?
Yes. No. No.
That’s how almost every family answers. And it’s exactly the situation where a silent alarm isn’t enough.
The good news
Fixing this takes 30 seconds
No electrician. No tools. You plug in a monitor that shows the actual CO number in your home, starting from 0. Not hours later. Not a green light. The real number, every time you walk past.
If it says 0, you sleep. If it doesn’t, you know.
If you close this page now, nothing changes.
You’ll go to bed every night this winter not knowing if the air your family is breathing is safe.
And with carbon monoxide, any one of those nights could be the last.
Peak CO season starts November 1
Know your number before the first cold night
★★★★★ 4.8 from 2,127 families
Heating-season pricing: up to 50% off until October 31
Sentivo Detector™ is a supplemental monitoring device and should be used alongside a certified CO alarm installed per local code. Not a medical device. If anyone has symptoms of CO poisoning, get outside and call 911.
Sold out 3 times already this year.Check if the CO detectors are still in stock.
Demand has been overwhelming. They had to be restocked twice already and there is no guarantee on how long this batch will last. Check availability below before it’s gone again.
Live inventory · Updated in real time
units left in this batch
Ships today if ordered before 5 PM · Next restock: mid-October
Sell-out risk
High
Next restock
Mid-Oct
Last sold out
Sep 14, 2026
Every cold snap empties our warehouse faster. If it’s available right now, don’t wait for the first freeze to decide.
Stock numbers reflect units available to ship today and update as orders are placed.
Most people who land here will close this tab.
Not because they don’t care. Because they tell themselves they’ll come back later.
Later is exactly when it’s too late.
Carbon monoxide doesn’t wait until you’re ready. It fills the house on an ordinary night, while the people you love are asleep.
This is the detector you just saw.
Sentivo Detector™. It shows the actual carbon monoxide level in your home, live, starting from 0 PPM. Not a green light that stays quiet for hours. It also catches natural gas and propane leaks. Plugs into any outlet in 30 seconds. No tools. No electrician. Battery backup if the power goes out. Works the night you plug it in.
One on every floor, and one outside the bedrooms. That’s the recommendation.
Every year, more than 100,000 Americans are rushed to the ER with carbon monoxide poisoning. Hundreds of them die.
Most of it happens at home. And none of them noticed anything until it was already too late.
You’ve seen the headlines. Every winter it’s the same story, in a different town every week: a family found unconscious in their own home. A couple who never woke up. Kids rushed to the hospital hours after the furnace kicked on.
And it always starts when the cold hits. More than half of all CO poisonings happen between November and February. (CDC) That season starts again in a few weeks.
They didn’t see it. They didn’t smell it. Nobody in the house knew anything was wrong.
If your home has anything that burns fuel (a furnace, a water heater, a gas stove, a fireplace, a car in the attached garage), the only thing standing between your family and the silent killer is whether someone notices in time.
Most CO poisonings happen at home, in houses just like this one.
“People who are sleeping can die from CO poisoning before they ever have symptoms.”
— U.S. Centers for Disease Control and Prevention
No headache to wake them. No dizziness to warn them. Just a quiet house, and an alarm on the ceiling that is still waiting.
Why this matters right now
The deadliest months of the year are about to start
Now
Sep
Oct
Nov
Peak
Dec
Jan
Feb
Mar
Apr
Heating season
Highest CO rates
>50%
of CO poisonings happen Nov–Feb. (CDC)
#1
non-medical poison killer in the U.S. (CDC)
14K+
hospitalized from it every year. (CDC)
The #1 source of CO in American homes? Heating systems that aren’t working right. The same furnace that’s sat untouched all summer, about to run every night for five months.
Why every winter looks the same for first responders
Don’t go into CO season blind
See how thousands of families are checking the air in their homes before the first cold night.
★★★★★ 4.8 from 2,127 families · 100-night guarantee
“But I already have a CO alarm.”
That’s what almost every family says. And it’s exactly why they feel safe when they shouldn’t. Because almost nobody knows what that alarm is actually built to do.
Almost every CO alarm sold in the U.S. is tested to a standard called UL 2034. And that standard requires your alarm to wait.
4 hrs
of allowed silence
At 30 PPM: required to stay completely silent
At 70 PPM: silent for the first hour, can wait up to 4
No number. No early warning. Just a green light.
Read that again. Your family can be breathing CO for hours while a perfectly working alarm says nothing. That’s not a defect. That’s the design.
And when did you last check yours? Most alarm sensors expire after 5–7 years. The test button checks the beep, not whether the sensor still works.
A quiet alarm doesn’t mean safe air. It means you don’t know.
It hits the people you love first
Your kids
Children under 10 have the highest rate of CO emergency room visits of any age group. (CDC)
Your parents
Older adults and people with heart conditions are more likely to become seriously ill.
A baby on the way
CO exposure is especially dangerous for unborn babies. (Mayo Clinic)
The early signs? Headache. Nausea. Tiredness. The same symptoms as the winter flu going around. Which is why so many families never realize what’s happening.
Families who saw it in time
23 PPM★★★★★
“Week one, 23 PPM in the basement. My $40 alarm upstairs? Quiet as always. Cracked heat exchanger.”
Marcus D. · Des Moines, IA
12 PPM★★★★★
“The dryer vent had come loose behind the wall. No symptoms, no beeping. Just a number telling us something was wrong.”
Andrea L. · Madison, WI
0 PPM★★★★★
“My dad is 78 and lives alone. Every Sunday I ask what the number says. Zero every time.”
Sarah K. · Pittsburgh, PA
Answer these 3 questions before bed tonight
1
Do you have a gas furnace, water heater, stove, fireplace or attached garage?
2
Do you know how old the sensor in your CO alarm is?
3
Could you tell me, right now, what the CO level in your home is?
Yes. No. No.
That’s how almost every family answers. And it’s exactly when a silent alarm isn’t enough.
The good news
Fixing this takes 30 seconds
No electrician. No tools. Plug in a monitor that shows the actual CO number in your home, starting from 0. The real number, every time you walk past.
If it says 0, you sleep. If it doesn’t, you know.
If you close this page now, nothing changes.
You’ll go to bed every night this winter not knowing if the air your family is breathing is safe.
And with carbon monoxide, any one of those nights could be the last.
Peak CO season starts November 1
Know your number before the first cold night
★★★★★ 4.8 from 2,127 families
Heating-season pricing: up to 50% off until October 31
Sentivo Detector™ is a supplemental monitoring device and should be used alongside a certified CO alarm installed per local code. Not a medical device. If anyone has symptoms of CO poisoning, get outside and call 911.
