This V-Groove Drive Pulley works both as an OEM replacement and as a general purpose pulley for power transmission such as compressors, industrial fans, lawn mowers, snowblowers, and electric motors. It has a hub attached and the inside diameter is 1''. There are no set screw holes. This part is Painted Black to prevent rusting. Additional Features: Made of Steel Works with 5L/B belts Heavy duty split steel Direct OEM Replacement for: Hustler Big Dog: 798975