The protector that I am refering to is made from stamped metal. It attaches to the seat stay a bit above the axle and is hinged at that point so that it can move up and down. In the down position it slips over the end of the axle nut covering the end of the nut and the toggle chain completely. There appears to be a set screw at the lower end to secure the protector in place while in use.
Paul Patzkowsky
Longmont Colorado