1)Oil , slient, safety, simple operation; 2)High performance, high durability, low maintenance; 3)No need lubricated oil Detailed Product Description Cylinders4-cylinderCast Iron ConstructionStandardRegulatorStandardUSA-MFGYesMax P.S.I.175 psiMax C.F.M.16 cfmASME Certified TankStandardWheels/HandlesStandardH/Duty Belt GuardStandardBattery SystemSealed Type15-Amp AlternatorStandard12-Volt Aux. ...