1.scope of application:application all type of door.no frame door can choose bracket.swinging door:90.for in-swing dooror out-swing door 2.fail-safe operation 3.unlocking mode:power to unlock,no noise 4.temperature rating:-40c-100c 5.voltage:12v/24v optional 6.different series different sizes 7.accessories optional:access control,power supply,remote control,ect 8.different finishing optional:sprayed ,plated ,ect... 9.delay function:the time delay is adjustable 10.intelligent control 11.anti-interrupted 12.lock position auto correction