Double-Cylinder Deadbolt doubles your security When you have a double-cylinder deadbolt installed on an entry door with a window, you needn’t worry about someone punching out the glass and sticking their hand inside to unlock the door. Double door lock cylinders require a key to open the deadbolt both from the inside and outside, so the potential intruder can’t get in by simply turning a latch. Double cylinder deadbolt has a polished brass finish, and includes an adjustable latch and radius corner strikes. 5-pin tumbler in each of the double cylinder locks. Includes 2 keys.