The Nikon Focusing Screen for F-501 and N2020 Type B Grid Matte Screen Focus Bracket is a vintage accessory designed for film SLR cameras from the 1980s. Made by Nikon in Japan, this focusing screen is compatible with the Nikon F-501 and N2020 models. It provides a grid matte screen focus bracket for precise focusing and enhances visibility for accurate composition when shooting through a 24x36 mm camera lens. This unit is a valuable addition to any Nikon F series camera owner looking for improved focusing capabilities.