Blum Left Lock Devise Tandem Slides is a standard locking device designed specifically for the 563/569 series drawer slides, featuring a left-side lock. This product convenient side-to-side adjustment of plus or minus 1.5 mm (1/16"), ensuring precise alignment. Each drawer requires one right and one left device, with the left device being self-aligning and the right device captive. It accommodates self-adjusting drawer length tolerance for a fit every time. Constructed with a steel base and equipped with synthetic, spring-loaded release levers, it s durability and ease of use. The minimum inside drawer width needed is 170 mm (6-11/16"), and the device allows for height adjustment of up to +3 mm (1/8"). Model Number: