The Minn Kota MKA-22 Mounting Adapter for MKA-21 allows hole patterns from previously mounted motors to be used with composite brackets. It's ideal for carpeted deck surfaces. Minn Kota MKA-22 Mounting Adapter for MKA-21: Ideal for carpeted deck surfaces For use with MKA-21 and RTA-17 composite brackets Allows for use with hold patterns from previously mounted brackets Center puck not included.