Pololu Wheel for Micro Servo Splines (20T, 4.8mm) - 40×7mm, Black, 2-Pack

These black plastic wheels have silicone tires and measure 40 mm (1.57?) in diameter. They mount onto micro servo splines with 20 teeth and a 4.8 mm diameter, such as the splines on FEETECH?s FS90R micro continuous rotation servos and FT90R digital micro continuous rotation servos. This product is a pair of wheels.