Comments about Manta, Atomic Spring Fin Strap:

The spring diameter was standard...same as the Apollo set. However, the Apollo springs have a twine protector inside the spring to keep it from being overstretched. I added my own to these springs, though it wasn't easy to do.

The springs have a S shaped metal clip on the end of the springs. You bend the open end of the S around the peg that you would otherwise attach your Atomic buckle to. You need a large set of pliers, like channel locks, to do this. Large channel locks...mine were either 12 or 14 inch. It's not easy to get the perfect bend. Be careful with the peg as it's plastic and you can dent it with the pliers.

There is a plastic sleeve around much of the spring, but I wanted something easier to grasp, so I took some 1 inch nylon webbing and cut a piece maybe 8-10 inches and then looped it around the plastic tube, overlapped the two ends about 3/4 inch, and then sewed them together and to the opposite side webbing. So, I was sewing through 3 layers of webbing. When done, it looks like a figure 8 with one loop tight around the spring, and the other loop sticking up and available for grabbing when you want to get your fins off. For sewing thread, I used dental floss.

Anyway, it does work. The S clips kind of cant to the side on the pegs, but they should stay. All in all, they do work and are cheaper than the Atomic spring straps.