Marks USA - Series 21AC - Ornamental Iron Mortise Lockset - Double Cylinder - Backset: 2-1/2" - Entrance - Satin Chrome - Optional Handing PDQ Compact design: 13/16"x29/32"x5/8" (30x58x16 mm)

Compact design: 13/16"x29/32"x5/8" (30x58x16 mm)

IMPORTANT NOTE: Clamps

Primus – same key sections as obverse except a ìPî has been added To Keyway # (ie: CP

Six plug-in terminals

Marks USA - Series 21AC - Ornamental Iron Mortise Lockset - Double Cylinder - Backset: 2-1/2" - Entrance - Satin Chrome - Optional Handing PDQ Compact design: 13/16"x29/32"x5/8" (30x58x16 mm)Marks USA has been a primary manufacturer of Ornamental Iron Storm Door locks for many years. During that time, many innovative improvements were developed to increase the reliability and ease of installation. Innovations includes the "Uni Lock" model with single screw assembly, elimination of threaded swivel spindles in favor of the more secure thru bolted design, helper springs in lever rose sets, and steel hubs for greater endurance.