The Fin Box Lock attaches to longboards, SUPs, wave skis, windsurfers - anything with a sliding fin box. There's no need to remove the fin: you just need a 35 mm space.
2 nylon side keys fit into the grooves on the inside of the fin box. A centre key locks them in place. It takes 10 seconds. The holes in the keys align to admit any 40 mm padlock, or cable locks up to 8 mm in diameter.
The Fin Box Lock is made from glass-filled nylon and won't break, chip or deform. The design has been copied by dozens of imitators, but the Gumby Lock Fin Box Lock remains the original - and best.
Don't bother making these yourselfBy: Funnel on 14 July 2017There are loads of forum posts saying how you can make yourself one of these but there is just no point. Just for the cost of the materials you could have bought a Gumby Lock.