There are two sizes: 2" (50mm) Scuff & Buff Ball with 2-1/2" (63mm) shaft and 3" (75mm) Scuff & Buff Ball is fitted with a 3-1/2" (88mm) shaft. Each shaft diameter is 1/4" (6.35mm). All five balls are replaceable and color-coded for the 60, 180, 320, 600 and 800 grits.
Tan - 60 grit, Green - 180 grit, Maroon - 320 grit, Grey - 600 grit, White - 800 grit