There's actually many. Cressi Gara, Seac Motus, Mako Freediver II, Mares Razor Pro - I'm sure there's others. The Seac and Mako are under $100USD and the Cressi is $150. Personally, I'd go with the Mako just because they are a good company to deal with.
I get the impression they're targeted at freedivers, as most are shown with a long blade installed. They're all fairly close in design but I'm not sure you could interchange blade brands (for example, cressi footpocket with seac blade)
I get the impression they're targeted at freedivers, as most are shown with a long blade installed. They're all fairly close in design but I'm not sure you could interchange blade brands (for example, cressi footpocket with seac blade)