The CTA Manufacturing Porsche Camshaft Sprocket Holding Tool, No. 7458, is designed to hold an impact socket in the center, ensuring accurate loosening of the bolt or accurate torque during installation and removal. The 19mm bushed socket prevents slippage and rounding off of the cam bolt at the end of the camshafts. The tool services 1996 to 1998 Porsche 911, 3.6L Flat 6 engines. Use with a 1/2" drive standard breaker bar, extension and/or torque wrench.