THIS IS A AEROSPACE COMPONENTS VACUUM PUMP,THESE PUMPS PULLS ABOUT 18 to 20" OF VACUUM AT 3000 RPM'S AND 38 CFM !! ,ONLY 1 OR 2 HRS OF RUN TIME ON A DYNO. WE HAVE ABOUT 30 ENGINE BUILDERS ON OUR VACUUM PUMP PROGRAM THEY USE THEM FOR ABOUT ABOUT 3 TO 6 MONTHS AND EXCHANGE THEM FOR NEW ONES, WE CAN'T SELL THEM AS NEW SO WE PUT THEM ON E-BAY VERY NICE PUMPS YOU WONT BE DISAPOINTED WITH THESE PUMPS. THESE PUMPS ARE REBUILT NEW VANES, BEARINGS AND SEAL. COMES WITH PULLEY AND -12 FITTINGS AND MOUNTING BRACKET AS SEEN IN THE PICTURES OF PUMP. WWW.AEROSPACECOMPONENTS.COM   TECH INFO: WHEN YOU ARE LOOKING AT THE FRONT OF THE PUMP, THE PULLY FACING YOU AND LONG ADJUSTMENT SLOT IS AT THE TOP, THE PORT AT THE 10 O'CLOCK POS IS THE EXHAUST , AND THE PORT AT THE 2 O'CLOCK POS IS THE INTAKE PORT.P.S.NOT FOR STREET USE!!!