This is a Two-piece Two-Blade 1½" Red Nylon Spinner with a Nylon Backplate INCLUDES: One spinner cone One backplate Two 3/32" x 5/32" S/T screws Instructions on header card SPECS: Spinner Diameter: 1½" Spinner Backplate Thickness: 1/8" Crankshaft hole: 3/16" (may be reamed to ¼") COMMENTS: Instructions state that this is a sport plastic spinner and not designed for use with high performance engines or engines with tuned pipes. Operation above 14,000 RPM is not recommended. NNA-6/14/94 ir/jl instructions updt tjt 072705