Ultra short size, is applicable to any more style . very outer remote controller and burglary- resisiting device, it is simple and convenient to install. he ultrasonic wave of whole high- power is welded , the intensity is high, seal waterproofly of good performancly. have obstruction design from person who shut, it is difficult for card to die. adopt the electrical machinery best in quality, strength is steady, can bear the big unexpected electric current to assault . Product Technical Parameter : working voltage: DC12V?3V Working journey: 18MM?1MM Push pulling force: 30N?2N Working temperture: -30 degrees- +80 degrees