Tamron's 200mm f/3.5 telephoto prime, catalogued as model 04B, launched alongside the Adaptall-2 system in 1979 and remained on sale until the mid-1980s. It followed an earlier 200mm f/3.5 sold under Tamron's original Adaptall mount system through the 1970s.
The 04B is a moderate-speed telephoto prime built for the Adaptall-2 interchangeable mount, accepting rear adapters for Canon FD, Nikon F, Minolta MD, Olympus OM, Pentax K, Konica AR, Contax/Yashica and M42. Its focal length and aperture made it a common secondary lens alongside Tamron's zooms of the era.
A prime construction at 200mm gives it an edge in contrast and close-up handling over the contemporary Adaptall zooms that reached the same focal length, without matching the speed of Tamron's later SP telephotos. It suits portraiture and general telephoto work on a budget.
Listings for this lens are less common than Tamron's popular zooms of the same era, so condition and included adapter vary. Check the focus helicoid for smoothness, look for haze or separation in the rear elements, and confirm any tripod collar, if fitted, is present and undamaged.