Bundle - 21 BLUM TANDEM Drawer Slides with BLUMOTION. Includes Slides 563H, Locking Devices, Rear Mounting Brackets, Screws and Instructions. by Blum Bundle - 21 BLUM TANDEM Drawer Slides with BLUMOTION. Includes Slides 563H, Locking Devices, Rear Mounting Brackets, Screws and Instructions. 21 Inch