Thule Pack 'n Pedal Rack Adapter Bracket - Magnet $9.95
Try not to get too attached.
Instead of hooks, Thule's Pack 'n Pedal panniers use magnets to hold the bags against the rack. So, if you are, or are going to be, using these panniers, you'll also need this Rack Adapter Bracket Magnet in order to keep the pannier in place. Besides, it never hurts to have a backup.