2500-2800 PSI / 2.3 GPM INCLUDES THERMAL RELEASE VALVE SPECS: FITS 7/8" SHAFT VERTICAL CRANK ENGINES WATER INLET / OUTLET FACE THE REAR OF THE MACHINE MOUNTING BOLTS: FROM MAIN CENTER SHAFT TO EACH MOUNT BOLT IS 4" - CENTER TO CENTER SPACING BETWEEN MOUNTING BOLTS IS: 7 11/16" - 6 3/16" - 6 7/16" In some instances, the pump may need to be removed to change engine oil. Some specific pressure washers may require longer bolts and spacers to mount the pump to your engine. These bolts and spacers are not included, but may be purchased at your local hardware store. Common bolt sizes: Two - 5/16" 18 x 2 1/2" , One - 5/16" 18 x 3 1/2"Himore