[WHAT]: Side Mount Self-Close Full Extension Ball Bearing Slides. 3-setions fold is convenient to fully open the drawer for easy access.The drawer slides equipped hydraulic damper which allows the slides achieve soft close effect. [WHY]:If you're tired of dealing with flimsy drawer slides that wobble and fail under pressure, it's time to upgrade to the Cold-Rolled Steel Drawer Tracks. The slides is made of 1.5 mm High - density cold-rolled steel with zinc plated finish, Rust resistant for your lifetime use. With dual industrial grade bearing ball inside, it will keep your drawers stable and safe even carrying up to 100 lb heavy weight items. [WHERE]:The slide rail is suitable for all kinds of home drawers and office furniture, It can apply to wardrobe drawers, keyboard drawers, cabinets drawers, goods shelf, wooden or steel drawer, toolbox drawers, RV, truck drawers that with demand for big load-bearing capacity, etc. [HOW]:①There is an installation video and an instruction for reference ②The length of slides can't be longer than the cabinet case depth(Please measure the length of the drawer without the frame board. And if the length is not even, please choose 1 inch shorter)③Reserve 1/2 inch of clearance for mounting on both sides ④The two glides must be mounted in parallel,or will damage the glides. [HOW MUCH]:You will get 4 pairs（8pcs) soft self close drawer slides ,And each drawer slides match with 12pcs screws. [WHEN]:If any question about product before drawer rails purchase or find any quality problem on our ball bearing drawer slides, please feel free to contact us, we promise solve it until you are satisfied. Note: When shopping for a drawer slide, make sure you select the correct length for your drawer box.