Material: Polyurethane cellular foam, spacers made of plastic, black. Consisting of: one buffer, threaded pin M12 x 55 mm, two spacers 12,5 mm (for mounting without guide roller) and one spacer 25 mm (for mounting with guide roller, using the supplied nuts M12). The required thread has already been machined on both face ends of the travel-wheel system. The srew-on buffer fits both travel-wheel-system sizes 200 and 250. Temperature range: -20°C to +60°C. Weight: 0,8 kg.