Thought I would mention this in case it has happened to anybody else. Purchased a Pakit Rak to mount to my Rivco hitch. The Pakit Rak hitch adaptor would not slide into the Rivco receiver. Had to loosen the receiver, slide in the Pakit Rak hitch adaptor, then tighten the receiver. And do the opposite if I wanted to remove the Pakit Rak and hook up the trailer. Pretty frustrating. I contacted Jerry Kougel at Pakit Rak ([email protected]) and he immediately shipped out a replacement hitch adaptor. Seems their Rivco hitch adaptors were made slightly off spec. (Not sure how long they've had this problem.) The replacement hitch adaptor works fine. Great customer service from Pakit Rak.