Is there a solid Barefoot, Open-Heel Fin with an adjustable (buckle) strap on the market?

[TheShark1]

Hey everyone! I'm looking to purchase some new rental fins for my resort. I'd love to purchase some Barefoot, Open-Heel Fins with an ADJUSTABLE buckle strap (to fit a wider range of feet). But I can't find a manufacturer who makes them?

The closest I can find is the Scubapro Go fins...Full-Foot Open-Heel fins...but the strap isn't really adjustable (just flexible bungee...not buckle...straps).

Thanks a ton in advance for any suggestions!