What's in an Ajax alarm kit, and what to add room by room

Each Ajax Superior alarm kit we sell, from Kit 19 S to Kit 27 S, contains a hub (the control panel), two motion detectors, a door contact, an indoor siren, an outdoor siren, and either two key fobs or a keypad to set and unset it. That covers one entry door and two rooms. For the rest of the property, add a detector for each other door, any glazing you want covered and any extra rooms.

The kits sit in our Ajax wireless alarm range. Prices include VAT, delivery is extra, and prices can change.

What comes in an Ajax kit?

All nine share the same door contact and two sirens. They differ in the hub, whether the motion detectors carry a camera, and the control.

We stock Kits 19 S, 21 S, 22 S and 25 S in white only; the others come in black or white.

Only the hub needs mains power. The Hub 2 (2G) Jeweller panel reports over Ethernet and two 2G SIMs, takes 100 devices and 50 users, and runs for up to 15 hours on its backup battery. The Hub 2 Plus Jeweller adds Wi-Fi and 4G, with room for 200 devices and 200 users. The other parts run on batteries and use Ajax's encrypted Jeweller radio, rated at up to 2,000 m in open space for the hub and 1,700 m for the motion detectors; walls and floors shorten both.

Which detectors are in the box?

• Superior MotionProtect Jeweller (Kits 19 S, 20 S, 21 S, 27 S): a PIR covering up to 12 m across 88.5°, set to ignore pets up to 20 kg and 50 cm tall. Ajax rates its battery at up to five years.
• Superior MotionCam (PhOD) Jeweller (Kits 22 S to 26 S): the same detection plus a camera with infrared lighting. When it triggers while armed, it sends photos to the app so you can see the cause. PhOD means photo on demand, a feature that stays off until you enable it.
• Superior DoorProtect Jeweller: a magnetic contact with two reed switches and a terminal for one wired contact, with a battery rated at up to seven years.

How do you set and unset it?

Every kit works with the Ajax app, plus one physical control:

• Two SpaceControl key fobs: arm, disarm, night mode and panic buttons. An extra fob is £47.31.
• Superior KeyPad Plus Jeweller: codes, Tag fobs and Pass cards, up to 200 personal codes and duress codes. It locks for 3 to 180 minutes after more than three wrong codes in a minute.
• KeyPad TouchScreen Jeweller: a touch display that also accepts Tag, Pass or a phone over Bluetooth.

Tags and Pass cards are sold separately: three Tags are £17.30 and three Pass cards £16.16.

Why are there two sirens?

• Superior StreetSiren DoubleDeck Jeweller: the outdoor deterrent, 85 to 113 dB at 1 m with an LED, IP54, on four CR123A batteries or an optional 12 V supply.
• Superior HomeSiren Jeweller: the indoor siren, 81 to 105 dB at 1 m.
• Both sound for 3 seconds to 3 minutes, can chime when a door opens while disarmed, and report if pulled off the wall.

What should you add, room by room?

In a two-storey house, fit the kit's contact on the front door and its motion detectors in the hall and living room, then cover every opening reachable from outside:

Glass-break detectors need a pane of at least 400 x 400 mm and listen across 180°. For smoke, heat and carbon monoxide, our Ajax wireless fire alarms also use Jeweller and can join the same hub.

What changes for a small shop or office?

• Pick a keypad kit (21 S, 23 S, 25 S, 26 S or 27 S) so each person has their own code, Tag or Pass, and the app shows who set or unset the alarm.
• Hub 2 Plus allows 200 users and 25 security groups, against 50 users and 9 groups on Hub 2 (2G). Groups let a stock room stay armed while the shop floor is open.
• Put DoorProtect Plus U on the fire exit and rear door, and GlassProtect U near shopfront glass, checking the glass type first: Ajax lists standard, insulated and tempered panes.
• Speak to your insurer first. The certification body SSAIB says an audible-only alarm is unlikely to satisfy an insurer for business premises, and insurers will usually expect a maintenance contract.

Can you fit it yourself, and will the police respond?

The only cables are the hub's mains lead and Ethernet, so a practical owner can fit a kit and run it self-monitored through the app. Police response is different. Under the NPCC Security Systems Requirements, published by Police CPI, an alarm company must be certified by a UKAS-accredited body before a force will list it as compliant. SSAIB explains that the installer then obtains a unique reference number (URN) for the system from the police; from 1 April 2026 the fee is £70.68 inc VAT. SSAIB also warns that a monitored alarm does not always bring a police response, and that three false alarms in a year (four in Scotland) lose the URN.

We supply the equipment and do not fit it. For a monitored system with police response, we can recommend a qualified installer depending on the job and area. If you add an outdoor MotionCam later, point it at your own property: the ICO says data protection law applies once a home camera records beyond your boundary.

Our take

Choose the control first. Fobs suit a couple; a keypad suits a family, lodgers or staff. MotionCam kits earn their extra cost if you will check alarms yourself, as a photo shows within seconds whether to worry. Pick Hub 2 Plus for Wi-Fi and 4G backup routes or more than 100 devices.

Not sure which kit fits? Send us a list of your doors and windows through our contact page or call 01902 902251. Zenith Security Co. is a security equipment supplier, trading since 2012 from our Wolverhampton trade counter, and we ship nationally to England, Scotland and Wales.

Quick questions

Does an Ajax kit need a phone line?
No. Hub 2 (2G) reports over Ethernet and two SIMs, and Hub 2 Plus adds Wi-Fi.

Are the kits Grade 2?
Ajax's specifications list EN 50131 Security Grade 2 for each device in these kits. Ask your insurer which grade they require.

Will my dog set off the motion detectors?
Both kit detectors can ignore animals up to 20 kg and 50 cm tall, fitted at the 2.4 m height Ajax recommends.

Do you fit Ajax alarms?
No, we are a supplier. We can recommend a qualified installer depending on the job and area.

Source: Ajax Systems blog: basic security system devices; Ajax product specifications; NPCC Security Systems Requirements (Police CPI); SSAIB: alarm systems; ICO: home CCTV systems.