100dB pieoelectric sounder. LED power indicator and signal transmission. Wall sabotage switch and Sheathing tamper switch. Radio ranging up to 70m. Works with three C type alkaline batteries. 868 MHz Radio grequency. IP54 Protection grade. Dimensions: 134 x 211.7 x 51 mm. Grade 2 certified according to EN 50131. not compatible with SP4000.