This is a Spinner Adapter Kit by Great Planes. FEATURES: Adapter kit for aluminum spinners. This steel adapter kit tightens the backplate & propeller onto the engine, then using a single bolt-on design, holds & centers each spinner perfectly on its baseplate. Machined for accuracy. This spinner adapter kit will fit the following engines: -SuperTigre S2500-4500 -Saito FA-300 Twins One year quality guarantee. Detailed instruction printed on the header card. INCLUDES: (1) Propeller Nut (1) Propeller Washer REQUIRES: 14mm Wrench To Tighten Propeller Nut An Aluminum Spinner w/Center Mounting Hole 10-32 Bolt SPECS: Shaft Size: M10-1.25 Prop Nut Length: 1-1/2" (38mm) COMMENTS: Aluminum backplate bushing is not required with this engine. JAL 9/13/99 ir/jl kr3/20/03