antenna extension

Wireless Smoke Detector for Tenement - Wanlin, a Chinese manufacturer and export supplier based in Shenzhen, China, builds Hong Kong wireless fire alarm and fire detection systems: LoRaWAN and RF 433 MHz wireless gateways with 4G or Wi-Fi uplink, battery-powered wireless call points and smoke and heat detectors, mains-powered alarm units with 2-hour UPS back···