Blackt Electrotech BT31C motion sensor Blackt Electrotech BT31C is new energy saving device, which turn on light or fan automatically with all integrated kit.when it’s kept on it will use its infrared rays and sense human motion. Once it senses human motion it automatically turns on the device connected to it. QUALITY CONTROL STANDARD: Operating volt: ac 220-250v 50hz-60hz. Load power: upto ...