ball bearing drawer slides rails damped by air Soft Closing with last 30 mm stroke Material: Work hardened cold rolled steel Mounting: Side, for frame and frameless construction Load capacity: 45kgs/450mm Finish: SPCC Electro-Zinc Plated with Bright / Black,Chrome Thickness: 1.2/1.2/1.5mm;1.1/1.1/1.4mm;1.0/1.0/1.2mm The installation gap: the installation gap between rail is 12.7+/-0.1mm Size: 200mm-900mm Option: 1" over travel Advantages: Automatic low noise closing action Pre-assembled, ready to install The BS4509 is a soft closing side mount ball bearing drawer slide. Features include, an oil filled soft closing cylinder with the last 30mm stroke, nonhanded disconnect release, and 100 lbs. load rating, slides are available in zinc, black and white epoxy finish. Sizes available for 12 to 28 in.