Dave Brown adapter nut is constructed of plain black, CNC machined steel. Use with 2-1/2" spinners and under. This prop adapter kit tightens the backplate and propeller onto the engine, then using a single bolt-on design, holds and centers each spinner perfectly on its baseplate. Will fit the following engines: OS Max .61-.90, SuperTigre .61-.90 and G2300 Fox .60-1.20.
Although it will depend on the thickness of your prop and the spinner size, as a general rule, always use the longest adapter nut possible.