Mechanical operation. Front and back plates to use with existing compatible locks. Non-handed. Clutch on handle. For internal and external doors. 8mm square follower. Stainless Steel PVD finish. Specifications: Front plate W x D x H: 48 x 72 x 177mm. Door thickness 35-65mm. For use with existing lock or latch with either fixing hole 22mm (7/8") below the follower or two holes 38mm (1.5") apart either side of the follower.