The HI 48 Teeth Pulley with bearing assembly fits the OF16S-L, OF16S-H, and the OF16 Pro machine.  It also fits the original OF20S-L, OF20 S-H, OF20 Pro series machines built before April 2015. This pulley has a profile of HTD 1.5mm and has 48 teeth. The inside diameter is 3/8''.