This 29T Mod1 Spool Gear allows you to fine tune the gearing of your vehicleFeatures:Strong and durable steel for long-lasting performance in extreme RC conditions - Precision manufactured tooth profile for smooth operation - Precision manufactured set screw holes for the fit of screws either side of the spool shaft for extra secure fit - To fit 8mm diameter shaftIncludes:1 x 29T MOD1 SPOOL GEAR (8mm BORE) 1 x M4 x 4mm Set Screw 1 x M4 Screw Pin