Hitch mounts inside the end of the left-side seatstay tube, using a split-wedge clamp similar to a handlebar stem. Fits Yuba Mondo models V2 and up.
Note that the towbar of the trailer will move over the left-side rack when turning, so you won't be able to turn very sharply to the left if you are carrying cargo on the rack and pulling a trailer at the same time.