what is the difference between a single cylinder and double cylinder handset? I can I know which I need to order?
A. Double-Cylinder locks mean there is a keyhole on both sides of the door (interior and exterior), so if you want to lock and unlock the door from the inside, you'll need to use a key. Single Cylinder means there is only a keyhole on the outside, and deadbolt is operated by a thumbturn from the inside. I hope this helps!

















