The Tokina SZ-X 75-300mm f/4.5-5.6 was a consumer telephoto zoom from Tokina's SZ-X range of the 1980s, extending reach for wildlife, sport and distant subjects on 35mm SLR bodies at a price well below the company's faster AT-X telephotos.
It uses a one-touch push-pull zoom-and-focus barrel with a manual click-stop aperture ring and standard period coating. Maximum aperture falls from f/4.5 at 75mm to f/5.6 at 300mm, requiring good light or a fast film to keep shutter speeds usable at the long end.
Sharpness holds up reasonably through the middle of the range but softens at 300mm wide open, and contrast can look flat in hazy conditions, consistent with budget long-telephoto zooms of the period. It rewards stopping down by a stop or two where light allows.
These sell cheaply across most manual SLR mounts. Buyers should check the push-pull barrel for play at full extension, confirm any tripod collar is intact where fitted, and inspect the rear elements for haze common on long-stored telephoto zooms of this design.