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How to fit a glass break detector

Updated: 20.10.2026

You are at a downstairs window, and the amazon.co.uk listing only said to peel and stick. That line is enough for a vibration siren that has to feel the pane. It is the wrong first move if the box is a SimpliSafe Glassbreak Sensor, which listens from the room. This page is how to fit a glass break detector of either kind, then test the window you care about. The [glass break detector comparison](/hub/burglar-protection/glass-break-detector) holds the five listings, from the König unit at £8.10 to the SimpliSafe sensor at £34.99. A qualifying purchase can earn a commission at no extra cost to you.

You are at a downstairs window, and the amazon.co.uk listing only said to peel and stick. That line is enough for a vibration siren that has to feel the pane.

Our top picks

SimpliSafe SimpliSafe Glassbreak Sensor

Best overall

SimpliSafe SimpliSafe Glassbreak Sensor
7.8/10about £34.99
View offer
Flintronic Flintronic 4-pack window alarm

Best value

Flintronic Flintronic 4-pack window alarm
7.2/10about £18.99
View offer
König König Glass Break Alarm

Alternative

König König Glass Break Alarm
4.3/10about £8.10
View offer
On this page
  1. 1.Stick-on sirens go on the glass
  2. 2.Place the acoustic sensor in the room
  3. 3.Test the product you actually bought
  4. 4.Batteries, pads, and your ears

Stick-on sirens go on the glass

Flintronic and Goerpn tell you to take the film off, stick the unit, switch it on, and wait for a beep after about five seconds. The alarm and light then run for about 30 seconds. That only works if the pad is on the pane, because the sensor feels the surface it is fixed to. The frame and the plaster beside the window are a different structure. Wipe the glass and let it dry before you press the pad. None of the five listings states a weatherproof rating. König’s SEC-AGB10 uses AAA cells you supply and a sensitivity UK reviews say you can select. Fit the cells before you press the pad on. The acoustic sensor or vibration alarm page is the fork if you wanted one listener for the room.

Place the acoustic sensor in the room

The SimpliSafe Glassbreak Sensor, model 8960, is acoustic. The listing says it is not a standalone sensor and that you need a third-generation SimpliSafe system. Set up the base station first, then add the sensor from the keypad. One CR123A is in the box. A UK review describes enrolment in about five minutes. Face the glass. SimpliSafe’s UK guide uses about 20 feet in a clear line, and about 5–10 feet with heavy curtains. The amazon table says a maximum of 10 feet. Do not stretch one sensor across a long lounge. The maker limits this sensor to ordinary single and double pane, not laminated glass. One sensor covers one room, and the UK page says to keep it out of the kitchen. The best glass break sensor page sets it against the stick-on packs.
SimpliSafe SimpliSafe Glassbreak Sensor

Testsieger

SimpliSafe SimpliSafe Glassbreak Sensor
7.8/10about £34.99
View offer

Test the product you actually bought

You can check that the SimpliSafe sensor enrols, faces the glass, and is clear of curtains. A clap is not the maker’s simulator, and this page will not invent a detection rate. Buyers in the file say they would not break a window to find out. For a stick-on siren, use a firm knock on the pane after the five-second arming beep. Goerpn reviews say it needs a hard thump, or a hit on the case. Flintronic UK reviews include a wheelie bin that set a unit off, and panes that would not trip. A silent hard knock on the glass it is stuck to is a failed test of that unit. If the result is random, read the glass break detector false alarm page. A dead unit left as a visual deterrent is not a detector.

Batteries, pads, and your ears

Seat the Flintronic battery cover before you stick the unit. One UK review says the cover came off when the activation tab was pulled. If a dead König pad will not release, warm the edge and slide a plastic card under it. Keep metal tools off the glass. Do not put your ear on a siren that claims 130 dB. Step back and let the 30-second cycle finish. One UK Goerpn review put the sound nearer 120 dB. Stop and call an installer when you need Grade 2 under PD 6662, or cover for laminated glass. None of these listings states that grade or BS EN 50131-2-7-1.

Common questions

Do I stick a vibration alarm to the pane or the frame?
Stick it to the pane. Flintronic and Goerpn are vibration sirens, and they feel the surface they are fixed to. The frame can stay still while the glass moves, so a pad on the timber is a different test from the window you meant to cover. Clean and dry the glass, then press and hold.
Where does the SimpliSafe sensor go if I have curtains?
Face the glass and bring it closer. SimpliSafe’s UK guide uses about 20 feet when the line is clear, and about 5–10 feet when curtains are heavy, so the microphone is not covered. Enrol it on the system before you judge the position. One sensor still covers one room, not the rest of the house.
Can I test it without smashing the window?
You can, within a limit. For a stick-on siren, use a firm knock on the pane after the arming beep, not a hand clap from the sofa. For the SimpliSafe sensor, check enrolment, facing, and curtains. A graded acoustic detector is commissioned with the maker’s simulator. A clap is not that test, and nobody smashed a window for this page.
Why did the battery cover fall off when I pulled the tab?
That shows up in a Flintronic UK review on the first tab pull. Seat the cover before you stick the unit. A loose cell looks like a failed sensor, and taking the pad off to refit the cover is how the adhesive starts to give up.
When should I stop and call an installer?
Stop when you need a graded system, a certificate, or cover for laminated glass that the SimpliSafe UK page excludes. These listings are audible pads or one acoustic add-on. They are not a PD 6662 installation. If the knock test fails and a second identical pack would only repeat it, an installer is the next step.

Related pages

Glass break detector buying guide

Glass break detector

Acoustic vs vibration glass break sensor: which one

Best glass break sensor UK: five listings compared

Glass break detector false alarm: noise or silence

Sources

Public UK sources. Listing prices, stars, and review counts are from amazon.co.uk, not a live check on 19 October 2026.

  1. BS EN 50131-2-7-1 — indoor acoustic glass-break detectors (retrieved 19 October 2026)
  2. NSI Bulletin 0040, PD 6662:2017 — glass-break and shock parts (retrieved 19 October 2026)
  3. ProtectUK — alarms and CCTV (retrieved 19 October 2026)
  4. Ask the Police Q75 — audible-only alarms (retrieved 19 October 2026)
  5. SimpliSafe UK — Glassbreak Sensor (retrieved 19 October 2026)
  6. Westmorland and Furness Council — alarm noise (retrieved 19 October 2026)
  7. GOV.UK — 1982 audible intruder alarm code (retrieved 19 October 2026)
  8. amazon.co.uk listings for the five ASINs in this comparison (retrieved 19 October 2026)