Mixed size Locker units in one tower, 12-Small size, 6-Medium size, 3-Large size (the size can be variable). With dual custody locking & padlock key cover, one guest key & one master key. Can be locked only with a guest key, but unlocking by both keys. Strong construction for hotel front desk to keep valuables of guests & other items like arms/ammo which they are not allowed to carry inside room.