This is my first iteration of a cup for my bungee straps I use on my Jet Fins and on my Mares fins. I use 1/4 inch bungee with two zip ties to form a loop for a one size fits me quick strap. Similar to the stainless springs that cost 60 bucks, but don't catastrophically fail and cost about 60 cents. These cups make them a little more comfy (I am a minimalist and use Adidas water shoes for around town, in the water, and diving) and give another area to clip on to for surf entries.