The AMS 2 Pro Feeder Unit is specially designed to support the AMS 2 Pro for printing multiple colors and materials. Ceramic-reinforced antiwear bushings are embedded in each feeder inlet to better protect the inlet from being worn by the filament after prolonged use. Each AMS 2 Pro has 4 feeder units, and each feeder unit has its own motor and gears to actively push the filament forward or wind it back to the spool.The AMS 2 Pro Feeder Unit has a sensor to detect filament. When a filament is inserted, the feeder unit will feed the filament automatically. When a filament needs to be winded back, the feeder unit will drive the AMS 2 Pro active support shaft to rotate the spool for filament winding.