I have three different types of holders (newer plastic Fidelty Elites, older metal Fidelity Deluxes and some Riteways) and they are all the same for my Graflock back. As I understand it, these are pretty much a universal holder design for spring backs. As someone mentioned, I'd be wary of the wooden holders or the ones designed for a specific camera by that camera's manufacturer such as Chamonix or Lotus (though I can't see why they wouldn't work - but just be wary). The sellers probably say "if compadible" just to make sure someone who doesn't know what he's buying gets the wrong type (not a spring back, different size camera etc) then tries to get a refund off the seller.