Wireless indoor siren that turns silent detection into immediate, unmissable warning — 105 dB at one meter, loud enough to wake a household, frighten an intruder, and signal urgency to neighbors. HomeSiren mounts discreetly indoors (often hidden somewhere unreachable to prevent disabling) and responds to any alarm event from the Ajax system: intrusion, smoke, glass break, panic — every trigger from every detector can route its alert to one or more HomeSirens. Sound level, alarm duration (3 seconds to 3 minutes), and tone are all configurable in the Ajax app per scenario, so a fire alarm can sound different from an intrusion alert without buying separate hardware. A built-in LED indicator confirms armed/disarmed status visually for users walking past, and tamper switches on both the front cover and the mounting bracket fire instant alarms if anyone tries to remove or open the unit. It pairs with the Ajax Hub 2 over the encrypted Jeweller radio protocol at distances up to 1,300m line-of-sight, runs up to 5 years on two CR123A batteries, with frequency-hopping and chip-level authentication blocking jamming and signal replay. IP41 rated for indoor installation, operates from 0°C to +40°C, up to 10 sirens per hub for full-property coverage. Ideal for villas, apartments, offices, retail spaces — any installation where the system needs to do more than notify; it needs to actively disrupt the intrusion in progress.