CompeX National disc tumbler ratchet lock is the perfect lock for sliding glass by-pass doors. Designed for 1/4" or thinner glass, this lock does not require any boring in the glass which means a simple tool-free installation. The ratchet bar attaches to the back door and is held in place with set screw which keeps the lock from drooping down when in the locked position. Can be keyed together with all National Lock disc tumbler locks( both cabinet and sliding glass door) using the same key blank. Comes in a bright nickel finish, stocked in 3 unique key numbers and includes 2 keys.