This Flat Idler Pulley is recommended as an OEM Replacement only. It comes with a bore adapter to bush down from 20mm to 3/8'' inside diameter. 31500203 features a heavy duty sealed radial single-row bearing.This part is Painted Black to prevent rusting. Additional Features: Made of Steel Flanges angled outward to help increase belt life Two bearings Direct OEM Replacement for: Bobcat Ryan: 2721541 Jacobsen: 2721541