High quality undermount slides at a great price. Woodtek® full extension, fully concealed undermount drawer slides feature smooth, quiet operation and built-in soft closing: Use in frameless (panel) or face frame cabinets. For drawers 12" to 21" long and drawer box sides from 13 to 16mm (1/2" to 5/8") thick. Minimum cabinet depth for standard overlay drawers is slide length plus 7/8" zinc coated steel profiles with permanently lubricated synthetic rollers and built-in soft closing mechanism. Ansi/bhma tested to 75 lb. slides mount to cabinet sides using #7x5/8" fh screws or with euro screws in line bored cabinets. (purchase screws separately. )drawers attach to slides by front locking devices included with slides. Front locking devices allow up to +3mm drawer height adjustment add optional 159-872 rear mounting sockets for face frame applications. 12"-18" length packed 10 pairs per box; 21" packed 6 pairs per box. Installation instructions included. (a copy can be viewed below) manufacturer's limited lifetime warranty. Imported.