The quick-fit US fin bolt is supplied with all of our fins to ensure an easy to use secure fitting.
Here is our video, which you can find in the Red Paddle Clubhouse, on how to fit a fin with a US fin bolt:
https://redpaddleco.com/clubhouse/maintenance-tips/how-to-fit-your-red-paddle-co-fin/
*it isn't necessary to use the black washer on the bolt.