SBR Series are light weight are made of highbut heavy duty extruded aluminum quality extruded aluminum alloy. Thesehousings, fitted with sealed standard units consist of sealed Ball BushingsBall Bushings for high running for higher running accuracy andaccuracy and extremely low friction. extremely low friction.When mounting these open type ofaluminum housings, the four securing Standard Coating : Anodizedholes should be provided with bolts toachieve the maximum load capacityand the best rigidity for every mountingposition.Standard Coating : Anodized.