After seeing an online review of this fin applied to an Itiwit x500 inflatable kayak, I first ordered the fin and then the holder when I realized that the fin didn't include it. I used Seamax marine glue.
Attaching the holder to the kayak was easy, and the bond remains very strong after several uses. Sliding the fin into the holder required a rubber mallet at first, but it gets a little easier with each insertion. I don't carry the mallet, but I still need something like my kayak seat to hammer the fin into position and to remove it (after deflating the boat). Hopefully, the fit won't become too loose with time. Some reviews complain of losing the fin in the water, but despite snagging, I can't imagine it coming loose with the boat inflated at this point.
The kayak must be deflated to insert or remove the fin, so I don't leave it on the boat, and I don't always want it anyway. It improves tracking substantially, but it can snag submerged trees and limbs or even the bottom in very shallow water. The kayak sits high in the water and only needs a few inches of clearance. The fin adds another five inches.
In the Okefenokee swamp, the fin snagged often enough that I eventually removed it, but tracking is rarely an issue in the swamp's narrow canals anyway. For deeper water on lakes and rivers, the fin improves tracking a lot. I've snagged submerged trees on the Oconee River, but in high wind or current, the tradeoff is worth it. Without it, I must paddle continually to stay on course. With it, I can relax for dozens of feet before drifting significantly off course.