Overview 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. Installation Learn more about the AMS 2 Pro Feeder Unit on Bambu Lab Wiki. In the Box - AMS 2 Pro Feeder Unit *1 - BT2-8 Screw *2 Compatibility AMS 2 Pro Product Specifications Materials Plastic, Metal Packaging Size 100*135*45 mm Color Grey Packaging Weight 0.147 kg