DO NOT BUY the Mantas SS springs for the post style fins like the Mares Quattro's. They will BREAK! The pin that is used to connect the spring and the clip is a worthless. It is just a steel pin that has SS "caps". It's not secure at all. My dive buddy just lost a fin last week due to it.
The caps used have sort of a "star" like cut in them. I think the idea is, once pushed on, they wont come off. Not true.
I haven't seen the Halcyon straps for the post. But don't waste your money on the Mantas.
As for the Mantas for the Jet Fins. They seem GTG... I have them on my jets and haven't had any problems.
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