The Union 2177 76mm 3 Lever Deadlock Satin Chrome is for wooden doors hinged on the left or the right, requiring key operation only. The lock is locked or unlocked by a key from either side. It has satin chrome forend & strike plates and the steel case is silver enamel painted. In general the 3 lever 2177 deadlock will be used for internal doors only, it is not recommended for external doors as it has no insurance rating. The 2177 deadlock will usually be used on cupboards, access panels, bedroom doors, study doors and other low security doors. Please order any necessa...