The Voigtlander Color-Skopar 21mm f/4.0 P Pancake Lens is an ultra-compact wide-angle lens, and is designed for use with the Bessa R4M/R4A cameras. It comes with the VM lens mount, for use on any camera that uses the Leica M mount. It is especially ideal for use with the Bessa R4M and R4A cameras, since these cameras have built-in bright frames for 21mm, and use of an external viewfinder is no longer necessary.