The ServoCity Dual-Bearing Timing Belt Idler Pulley (8mm Bore, 18.5mm Diameter, 9.5mm inside Width) is engineered with dual 8mm round bore bearings and a polycarbonate pulley. It is designed to adjust the tension and direction of a timing belt when mounted on an 8mm shaft or standoff. The pulley features a smooth surface for optimal belt movement and flanges for secure belt positioning. The bearings ensure smooth rotation even under axial loads, with one bearing flush and the other recessed for varied offsets.