Polaroid CB80 back for Holga
Polaroid introduced a camera back, the CB80, for the popular Holga cameras. Designed to use Type-80 peel-apart films, the back included a diopter lens, battery holder/6x6 mask, dark slide, and featured a tripod mount.
It was most often sold with a Holga 120SF (hence the included battery holder), however the back can be purchased separately. The CB80 can be used on any Holga 120-series camera.
When first introduced, the image produced by a CB80 did not cover the full frame of the Type-80 film. Shortly after its release, a modified CB80, called the CB80 Full Frame, was introduced that matched the full size of the film.
Due to the design of the back, the Holga viewfinder is completely obscured when the two are used together. An external Holga "viewfinder" can be purchased that mounts onto the CB80 and provides an accurate view of the scene.