Solarbotics GMPWB BLACK Wheel with Encoder Stripes with Silicone Tires.
This 25/8 plastic wheel is made specifically for the
Solarbotics GM2 GM3 GM8 and GM9 gearbox output shafts
and it also matches the Pololu plastic gear motors.
Each wheel has a silicone tire and 64stripe encoder pattern molded in.