Material: Rails made of cold-rolled sheet steel with a black galvanized surface. Light and quiet ball bearing. Very practical: The rails can be mounted at different heights so that you can use both flat keyboards and mice and "thicker" gaming keyboards - Very easy to assemble - screw the wooden board into the guide bracket (screws included). The ball outlet stops and locks automatically at both ends (extended and retracted). The telescopic rails are suitable for keyboard drawers, tablets, desks, work tables, etc. Scope of delivery: 1 pair of telescopic rails (right/left), 4 supports