Ametric&reg; 21XL037 Aluminum ANSI Timing Pulley with Flange, 21 Teeth, .25 Inch +/-1/16 Pilot Bore (d), 1.32 Inch Outside Diameter (De), 1.34 Inch Pitch Diameter (Dp), 0.5625 Face Width (F), (Ametric&reg; 1-081)