Metal Bay-1 convert adapter Bayonet type camera mount 52mm filter screw thread Fits all cameras that accept Bay-1 Use 52mm filters on Bay-1 cameras Converts Bay-1 filter mount to 52mm screw mount. Use 52mm accessories on your Bay 1. Fits all cameras that accept Bayonet-1 Bay-1. Compatible for use with Rolleiflex, Yashica 124, Rollei, Mat 124G, Rolleicord, Yashica 124G. Step, stepping adapter ring.