I picked up a used set of Jetfins (made in taiwan version) a bit ago in size XL, and removed the spring straps that came with them and replaced them with XXL to fit my boots better. I never used the original XL straps, but they were previously used. They look to be in fine shape and can provide pictures if needed. They'll come with the 4 bolts to attach to fins as well (also used/came with fins I purchased). Asking $25 + shipping.
For reference, they look like this
For reference, they look like this
