This is the 10x1.25x50mm Hex Cap Screw Adapter Kit from Tru-Turn. FEATURES: Black steel washer and hex cap screw. The screw is tapped 10-32 for cone screw. Used to mount Tru-Turn aluminum spinners onto the following engines: Zenoah G45 and G62 The design of this adapter kit is based on the use of a spinner and prop that is normally best suited for the engine in question. Use this adapter kit to fit Tru-Turn products with your engine. INCLUDES: (1) Screw (1) Washer REQUIRES: 17mm Wrench To Tighten Bolt Tru Turn Spinner SPECS: Screw Length: 2" (50mm) Washer Size - Inner Diameter: 10mm Thickness: 1.25mm Approx. Weight: 1.2 oz COMMENTS: In addition to this adapter, your Zenoah G45 or G62 engine requires a precision modification to the backplate of the spinner. The .375 hole must be precision reamed to .394 & it must be done accurately. For the Zenoah G38 engine, use TRUQ4035. For the Zenoah G23 engine, use TRUQ4025. JAL 5/19/99 ir/jl