Looking for a siren? Search B0887SMPKK for the indoor Siren Alarm, or search B092QR82P1, B09V2DXPPW, B0BWYLT3JB, B0BZHPQ1PK for outdoor models. Looking for a fob to arm/disarm your Vibration Sensor? Search B0978V4WQC for the FlexFob or B092M1QQ5M for the AlarmFob or B0BRCX6HVK for the SirenFob (siren products, required, not included). REQUIREMENTS: Android or Apple smartphone, wired ethernet port or stable WiFi connection (2.4 GHz band, only). LONGEST RANGE, BY FAR! YoLink devices use a new wireless technology called LoRa. Boasting an open-air range of up to 1/4 mile, and superior obstruction penetration, you can put sensors in places, like basements, outbuildings, several floors away, not possible with WiFi or older wireless systems. DEVICE-TO-DEVICE PAIRING allows for two or more devices, like your Vibration Sensor and a Siren Alarm, to be paired together, so they will operate when needed, without WiFi, internet, even without AC power (battery-powered or backed-up devices)!. DETECT & MONITOR: Attach to equipment like a generator, pump, or washing machine, to monitor and be notified of activity. Attach to windows to detect glass breaking. Please in or on objects like storage boxes or drawers to detect theft or attempted access to your possessions. WHY PAY A MONTHLY FEE, when you can protect it for free? Self-monitor and save when you take advantage of our many ways to be notified of alarms and off-normal events in and around your home or business. See the "Know Now!" section below for more info!.