Great Planes Set Screw Propeller Adapter 3.175mm Input/5mm Output FEATURES: Mounts onto the 3.175mm shaft coming out of a gearbox or motor shaft using a set screw; The propeller mounts onto this with the included nut INCLUDES: One Prop Drive One 1.5mmx3mm set screw One 5/16 Propeller Nut INCLUDES: One Prop Drive One 1.5mmx3mm set screw One 5/16 Propeller Nut