Enhanced Design 4-Vane Vacuum Pump Kit, Natural Aluminium Finish, Mounting Bracket Included Enhanced Design pulls 13.9% more vacuum Can be used efficiently on wet or dry-sump engines Achieves greater vacuum sooner, virtually maintenance free 4-Vane design weighs less than original style pumps Designed with maintenance-free precision sealed roller bearings Natural Aluminium finish designed to be polished, interior hard coated for wear resistance 4.375 O.D. body, 5.050 from back of pump to pulley mounting flange