Robinson"s Aluminum Pro pinions feature lightweight aluminum construction with an added hard coating that produces extra strenght and less friction. These pinions also feature a hollowed out core that reduces rotating mass for improv- ed acceleration and deceleration. Available in 48 pitch from 12 to 35 tooth sizes, and in 64 pitch in 16 to 47 tooth sizes. KPM 1/15/92 YOU WILL RECEIVE: 1 48pitch pinion 31 teeth 1 4-40 set screw COMMENTS: This is the "Silencer Series" pinions. Replacement set screws RRPC1000. update AXY 7/26/94 &