Abstract: A lock comprising an elongated, parallelepiped housing with an internal sliding latch with a centrally located shackle pin that is selectively secured with a tumbler casing to immobilize the latch to secure a door. The housing comprises a base that is affixed to the door and a faceplate set-off from the base by an integral top and parallel bottom. The top, bottom, faceplate and base establish a channel in which the latch moves. The latch comprises a planar body with spaced apart ends. One end comprises a bolt that inserts into a conventional keeper secured to the facility wall. The other latch end comprises an outwardly protruding handle that facilitates user manipulation. A pair of spaced apart slots are defined proximate the latch ends to permit the mounting bolts to extend through the latch and an oval-shaped slot defined adjacent the latch center permits a shackle pin to extend therethrough. The shackle pin secures a removable tumbler casing that immobilizes the sliding latch.