Fits 8" diameter banjo rims. Attaches between banjo bracket hooks and tension hoop, hooks fit through 2 oval slots in side of armrest. No attachment hardware needed for most banjos. NOTE: If you have two hooks spaced between 2-5/8" and 3-3/8" apart, this is likely to work for you. The 2 hooks may be next to each other or have another hook in between them.