This is a Arca-Swiss Polaroid back for Hasselblad Cameras. It is is for 500 series and 2000 series cameras. ARCA-SWISS started producing professional cameras in the early fifties. The new Swiss All-Round-CAmeras, ARCA-SWISS, rapidly gained an excellent reputation based on their precision and handling in practical situations. The first large-format reflex cameras, 6x9cm and 4x5" appeared in 1960 and were the rage of Photokina. Panoramic cameras and riflescopes followed soon thereafter. Many companies were awarded ARCA-SWISS subcontracts given the large potential for innovation. Philippe Vogt took the company over in 1984. A new era characterized by an extensive redesign of the entire line commenced.
This is a USED back, heavy signs of use on the casing, and it needs a thorough cleaning, but it all seems to function as it should.