Pentax's fast K-mount telephoto — a manual-focus 200mm f/2.5 with Super Multi Coating.
The SMC Pentax 200mm f/2.5 is a fast telephoto prime for the Pentax K bayonet mount, from the first-generation K-series range. At f/2.5 it was a bright, specialist 200mm aimed at sport, wildlife and low-light telephoto work.
This is a manual-focus lens with a 200mm focal length and a fast maximum aperture of f/2.5, carrying Pentax's Super Multi Coating. As a fast telephoto it is a large, heavy lens; confirm element count, filter arrangement and weight on the specific sample rather than assuming.
The 200mm reach combined with an f/2.5 aperture gives strong subject isolation and enough speed for action in poorer light, suiting sport, wildlife, tight portraits and available-light telephoto shooting. The wide aperture also brightens the viewfinder for focusing.
Fast professional-grade telephotos like this are uncommon and command strong prices, so verify condition and completeness carefully. Check for haze, fungus and coating wear across the large elements, confirm the aperture blades are dry, and test the focus mechanism. It fits Pentax K digital bodies and adapts to mirrorless.