V-Belt Idler Pulley Bearing Type Ball For V-Belt Type Classical Bore Diameter 17 mm Face Width 0.86 in For Belt Trade Size B Outside Diameter 4 in Pulley Material Fiberglass-Reinforced Nylon Bearing Material Chrome Steel Bearing Number 6203-2RS Features ABEC-1 Bearing For Use With Self Adjusting Belt Tensioner Material Fabrication Molded Material Grade 6/6 Maximum Operating Temperature 225 Degrees F