SBR 20-4000 WERB | Linear Motion Guide RailWERB SBR 20 4000 Supported Linear Round Shaft, 20 mm Diameter, 4000 mm Length The WERB SBR 20 4000 supported linear round shaft is a 20 mm diameter SBR rail on an aluminium support base, supplied in 4000 mm length. It is widely used on compact and medium CNC machines where long travel and good rigidity are required. As the authorised WERB linear motion supplier in Pakistan, Abdul Traders keeps SBR 20 4000 rails available for customers in Lahore,