The Powertrax No-Slip reuses the factory 8.25 C-clips, which are ever so slightly larger than the window machined into the Active Slotted Spacer (that’s part of the locker). It’s just small enough that the C-clip will pass through the window with a little force, but won’t for love nor money come back out. Unbeknownst to us, grinding a little of material off the C-clip so that it would easily pass through the window in the Slotted Spacer would have saved us hours of work lying on our backs under a Jeep. Finally, we had to drill the C-clip out of the locker. It sucked.