Self-adhesive closed mini-cell foam contoured hip wedges that can be further shaped and customized with the supplied sandpaper.
I'm new to whitewater kayaking, but the hips pads seem to have done the job. I couldn't use the full pad but was able to sand them down as needed to provide the desired fit.
These work well in my play boat. The pre-applied glue seems to be holding up very well. The included sandpaper allowed me to shape the pads very effectively to fit how I wanted. Just as an FYI, once sanded the pads become much grippier, which can make it hard to slide yourself in your boat if you want a really tight fit. I may sand them down a little more or put some duct tape on them to so I will slide in the boat more easily. I'd buy these again in a heartbeat.