This Flat Idler 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 will not require any bore adapter or bushing for use. 391222 features a light duty radial sealed double-row bearing, and will have no need for a bushing. This part is Painted Black to prevent rusting. Additional Features: Made of Steel Has two flanges Direct OEM Replacement for: Billy Goat: 521121