Pololu Magnetic Encoder Disc for 20D Metal Gearmotor OD 9.7mm, ID 2.0mm, 20CPR (5pk)

The Magnetic Encoder Disc for 20D Metal Gearmotor OD 9.7mm, ID 2.0mm, 20CPR (5pk) can be used with 20D mm metal gearmotors (extended motor shaft versions only). Appropriate Hall Effect sensors are required to complete the system. The discs are 2 mm thick with a 9.7 mm diameter, and the hole through the center enables them to securely press-fit onto 2mm-diameter motor shafts. Pack of 5 magnetic discs for 20D Metal Gearmotors (extended motor shaft versions only); Consists of ten evenly spaced magnetic pole...