XT panels have larger grit for faster results. Use with hubs: 2" Narrow 2W for 2-3" Pipe - 1/3" Shaft (1000820050), Hubs 3" Short for 3-4" Pipe - 1/3" Shaft & 1/2 Shaft (1000835050A) & (1001235050A). Sold in packages of 12 panels.