This is the standard telephoto lens available for the mamiya/sekor TL series cameras. It is the same internal design as the respective lens from the DTL series (black design). This version has a larger minimum focusing distance of 1.8 meters (6 feet) compared to 1.5 meters (5 feet) for the DTL series version.
The lens comes with a metal screw-in lens hood as well. There is also an A/M switch for the aperture control.
Ron Herron was so kind to provide a document which shows all interchangeable lenses available for the TL series (download WinZip file: 423 KB).