63.5 mm hub (2-1/2") supports fiber disc face plates with diameters of 101mm (4"), 115mm (4-1/2"), 127mm (5"), 178mm (7"), and 229mm (9")
Face plates are sold separately
M14-2 interior threaded metal insert fits grinders with M14-2 threaded spindle, typically sold in Europe and Latin America
Metal retainer nut securely fastens a fiber disc with a 22mm (7/8") center hole to a grinder/sander spindle
Retainer nut is compatible with 32mm (1-1/4") spanner wrench with 6.5mm (1/4" pins)