Recommended by firefighters

Protect your family from the silent killer

4.8 · 2,127 verified reviews

Free shipping

100-night tria

Lifetime warranty

Shop Necknix Detector™ — 50% off
Title

As featured in

Title

The part nobody tells you

Your alarm is built to stay silent until it’s almost too late.

Carbon monoxide harms the body long before a standard alarm reacts — and it can legally wait hours to sound. That’s why seeing the live number matters.

30 PPM

Headache, fatigue, nausea

50 PPM

Physical stress increases

70 PPM

Most alarms finally react

Meet necknix Detector™

The detector with a display.

Plug it in, see the live number, and know at a glance that you’re safe — or act fast if you’re not.

See CO from 0 PPM — not a yes/no light

Watch the live number climb long before an old alarm would beep.

Plugs in anywhere in 30 seconds

Any standard outlet. No ladder, tools or electrician — one per floor.

Won’t false-alarm when you cook

Reads carbon monoxide and gas — never smoke or steam.

4 sensors in one device

CO, gas, humidity and temperature together. Most detectors catch only one.

100-night risk-free trial

Not right for you? Full refund, return shipping covered — plus a lifetime warranty.

The silent killer

You can’t see it. You can’t smell it. And it doesn’t hurt.

CO leaks from furnaces, water heaters and stoves — and a dead sensor keeps glowing green anyway.

400+

Deaths every year in the US

100k+

ER visits a year — often mistaken for the flu

5–7y

Then the sensor dies — silently

Real families. Real protection.

4.8 · 2,127 verified reviews

✓ All reviews verified — from paying Necknix Detector™ customers

Protect Your Family. Get Your Necknix Detector™ Today!

CHooSE FOR YOUR HOME:

FOR ONE ROOM ONLY

1-PACK

Necknix™ 4-in-1 Air Detector

$54.95

/detector

Total

$118.00
$81.00

In stock · ships within 24 hours

What’s included

✓ 1 Necknix Detector™ detectors
✓ 100-night money-back trial
✓ Lifetime warranty

APARTMENTS, CONDOS

2-PACK

Necknix™ 4-in-1 Air Detector

$49.99

/detector
$236.00
$147.00

Total

SAVE $75

In stock · ships within 24 hours

What’s included

✓ 2 Necknix Detector™ detectors
✓ Free Shipping
✓ 100-night money-back trial
✓ Lifetime warranty

FULL HOME COVERAGE 

4-PACK

Necknix™ 4-in-1 Air Detector

$42.50

/detector

Total

$471.00
$250.00

SAVE $165

Offer ends in:

00
00
00

In stock · ships within 24 hours

What’s included

✓ 4 Necknix Detector™ detectors
★ Free placement guide
✓ Free Shipping
✓ 100-night money-back trial
✓ Lifetime warranty

YOUR HOME + PARENTS' HOME

8-PACK

Necknix™ 4-in-1 Air Detector

$38.73

/detector

Total

$941.00
$456.00

SAVE $355

In stock · ships within 24 hours

What’s included

✓ 8 Necknix Detector™ detectors
★ Free placement guide
✓ Free Shipping
✓ 100-night money-back trial
✓ Lifetime warranty

Your Purchase Is Protected By Our

100-Night “Sleep-Easy” Guarantee

At Necknix, we make sure our customers feel safer — or we refund 100% of their purchase. We’re so confident you’ll finally sleep knowing your family is protected that we’ll bear all the risk.

Got Questions? We got you covered!

How is this different from the detector I already own?

Your current alarm stays silent until CO hits around 70 PPM — and even then it can legally wait up to 4 hours before sounding. It only ever says “fine” or “emergency,” nothing in between. Necknix Detector™ shows the actual number on a display from 0 PPM, so you see a problem building while it’s still just a problem. And unlike a sealed green-light unit, you can always see it’s actually working.

Where do I put it? What height?

Plug it into a standard wall outlet at or slightly above eye level — outlet height is fine, because CO mixes evenly with air, and you want the display where you’ll actually glance at it. Put one near each sleeping area and one near your main fuel-burning appliance (furnace, water heater or gas stove), plus one per floor. Avoid placing it right next to the stove or in a bathroom. No ladder, no drilling.

How many do I need?

Simple rule: one per floor, plus one near every sleeping area and one near your main gas appliance. A typical 2-story home with a basement furnace needs about 4 — basement, main floor, and outside the bedrooms. Apartments often do fine with 2.

Will it false-alarm when I cook?

No. The sensor reads carbon monoxide and gas — not smoke or steam — so searing a steak or a steamy shower won’t set it off. And because you see the actual number rise and fall, you understand what’s happening instead of being startled by a random blare.

How do I know the sensor still works?

This is the whole reason Necknix Detector™ has a screen. A standard detector’s test button only checks the speaker. With Necknix Detector™, the live number is your proof of life: if it’s showing a real reading, the sensor is working, every day.

What if it doesn’t work for me?

Plug it in tonight and live with it for 100 nights. If you’re not completely happy for any reason, send it back — we refund every cent and cover return shipping. After the trial, every Necknix Detector™ is covered by a lifetime warranty.

Can I use it in a rental or RV?

Yes — both. It just plugs into a standard outlet, so there’s no drilling, no hardwiring and no landlord approval needed. It’s also popular for RVs, campers and cabins, where CO from a generator or propane heater is a real risk.

How do I contact support?

Real humans, usually within the hour during business hours. Please contact out Customer Service Team.

Is Necknix™ 4-in-1 Air Detector the same as Necknix Haven?

Yes — Necknix™ 4-in-1 Air Detector is simply the new name for the product you knew as Necknix Haven. Same product, same quality, same team behind it. As we grew, other sellers began copying our product and trading on the Necknix Haven name, which created confusion for customers trying to find the real thing. So we've brought everything under Necknix™ 4-in-1 Air Detector — a name that's fully our own and protects you from imitations. You may still see “Necknix Haven” on some packaging or older materials during the transition; rest assured it's the exact same product, straight from us.

From the community

Real questions. Real people.

2,847 comments · sorted by Top

MT

Marcus T. Chicago, IL · 2 days ago

Can someone vouch for this? Saw the ad three times today and my wife is pregnant so I’m not taking any chances with our gas furnace. Is it actually legit or just another drop-ship detector?

342

Reply

DK

Dan K.

✓ Verified

1 day ago

@Marcus works awesome man. Ordered the 4-pack after my brother-in-law had a scare with his water heater. One per floor + one in the hallway outside the bedrooms. Reads 0 PPM consistently. Get the 4-pack — you’ll want one near the nursery.

218

Reply

RS

Rachel S.

✓ Verified

1 day ago

Seconding Dan. Had mine 2 months. Quiet, no false alarms, and the digital readout is the reason I bought it over the beeper ones. Congrats on the baby

127

Reply

JP

Jen P. Boston, MA · 4 days ago

We have a gas stove and I’ve been paranoid ever since I read that study last year. My regular alarm has NEVER gone off but I don’t feel safe. Does this actually show the low levels you can’t smell?

201

Reply

TV

Tom V.

✓ Verified

1 day ago

Yep. Got one near our gas stove. Reads 2–6 PPM when the burners are going and drops back to 0 within 10 min of turning the hood on. Honestly kind of eye-opening. We run the hood every time now.

156

Reply

BH

Bill H.

✓ Verified

6 day ago

32 years retired from the fire service. Responded to more CO calls than I can count. The digital PPM readout is the right idea. Standard alarms only trigger above 70 PPM sustained. By then the damage is starting. Bought the 4-pack for my kids’ houses. Sleep better knowing it’s there.

412

Reply

DR

Diane R.

✓ Verified

2 weeks ago

HVAC tech here. Saw one of these in a customer’s basement last month, didn’t think much of it. Two days later it caught a back-drafting flue on a tankless water heater. Now I recommend them on every gas appliance job.

287

Reply

KM

Kevin M.

✓ Verified

4 days ago

Anyone with the 8-pack got a placement diagram for a 2-story + basement? Where do you put #5 through 8

94

Reply

Showing 8 of 2,847 · 94% of customer recommend Necknix Detector™

Who it’s for

If you burn anything, this is for you.

Parents

Peace of mind in every room your kids sleep in.

Gas-heat homes

Furnace, water heater or stove? You have a CO source.

Aging parents

A number they can read to you over the phone.

Renters

Plugs in, no install, comes with you when you move.

RVs & cabins

Generator and propane risk, wherever you are.

Protect your family tonight

Know what’s in the air your family breathes.

See the number. Every day, in every room that matters

Shop Necknix Detector™ — 50% off