These pucks provide a secure upper attachment point for Old Man Mountain (and many other) racks on frames without mounting bosses. 

Included in the packet are 8 heavy duty zip ties, clear protective film, and mounting hardware. Designed for use with carbon, steel, titanium and aluminium bikes and forks. Slots in the puck also allow for use with metal hose clamps (not with carbon forks!). Once installed, the pucks can be left on the bike, making it easy to remove and reinstall your rack whenever needed.

The pucks can be used to mount front or rear racks.

For use only with specific Panduit brand 120 lb zip ties. Panduit #BT2LH-TL0. Google them, they're pretty widely available.