I was thinking that is not so good to have a custom board (with a fin box) with a hardware store items…so I designed a functional and nice to look jewel
the functional part is that you dont need a screwdriver anymore
and you can move the fin IN the water.
-and you obtain a Silver piece of jewellery that has better look than a screw and is stainless of course
the piece has less thickness than all the fins so remains hidden and do not disturb the water flow
here s sample pictures
I d been using it for about 5 months or so