This is a A-PLW4-12 Pulley PN: PLW4-12Main Description As Following : A-PLW4-12 Pulley P.N: PLW4-12 This pulley can be used with either A or B width belts due to its dual groove / taper configuration.Hub Required: WOutside Diameter: 4.5" Crossed From: WSP450W , , 21020045 , , 21020045 , , 21020045 , , 2827-44127 JOHN DAY , 673-S85010500 , , 673S85010500 , Found in Section & Models : Chains/ Sprockets/ Pulleys/ Hubs > Pulleys, (Miscellaneous) (UNDEFINED): SEVERAL Associated Items : New Also This is An Aftermarket Product And : This pulley can be used with either A or B width belts due to its dual groove / taper configuration. Hub Required: W Outside Diameter: 4.5"