I ordered the Slide In Box adapter for my ITIWIT kayak in addition to my e-Fin with US box. I had to adapt the adapter a little so that it would fit into the mount, but it wasn't a big deal, the US Box fits perfectly in a SUP and finally a few things about the e-Fin, it's just fun, the remote control is easy to operate. If you run it at 400 watts, you can easily take 2 people with you. As I have this fairly new, I have noticed that the battery on the remote control runs out more quickly than the e-Fin, but I will keep an eye on that. We have now been on the water for more than 2.5 days and es still had 3 points out of 5.