The S&S VVT Cam Phaser Tool holds the cam phaser assembly in place on 24-later Harley Davidson Milwaukee-8 VVT engines 117" & 121" (including 2023.5 CVO models) allowing you to pull the Spool Valve Bolt and get access to the cam plate, oil pump, and, of course, the cam. A necessity to change the camshaft on H-D VVT engines.