Wakeboard thumbscrew. The threads are about 3/4” in length.

These will work on some older wakeboard bindings and fins.  Check thickness of your board if using for fins.  For boards that are not very thick these will work for your fins.

For wakeboards will work with the old flat style plates that just have holes in the baseplate.

Will work for older wakeboard fins that use 1/4 20 threaded screws.