The SBT rocker arm shaft is a replacement shaft compatible with the late model Sea-Doo 4-Tec motor. This is the shaft that regulates oil pressure through a 2mm hole in the PTO end of the shaft. This rocker shaft is used on all 2006 - to - present 4-Tec motors. Always remember to use new stretch bolts when replacing this shaft. NOTE:This shaft can be used on all early model 4-TEC motors if the oil pressure check valve is removed from the engine block. DO NOT use with the check valve installed.