This is Du-Bro"s 6mm x 1 Aluminum Spinner Prop Nut. FEATURES: Plain silver aluminum spinner. Meets AMA safety specs. CNC machined from 6061 T6 aluminum. Works with standard electric starting cones. This will fit the following engine models: Enya- .15, SS.15, .19, .19X, .21CX, .25X HP- VT.21 4S, VT.49 4S, .40FRT Gold Cup 2C, .61 FRT Gold Cup 2C Moki- .51 RC MVVS- .15-.61 Rossi- .21 YS- .53 INCLUDES: (1) Aluminum Prop Nut SPECS: Approx. Weight: 1oz Shaft Size: 6mm x 1 COMMENTS: Tighten nut with a screwdriver, ball driver or steel rod. 06-09-98kzh ir/jl kr3/17/03