There isn't a specific series of lenses. The KA mount was introduced in 1983. Any Pentax lens after that date will almost certainly have the KA mount. These lenses have 'SMC Pentax-A' engraved on the lens near the front element, and have a green 'A' engraved on the aperture ring just beyond the highest number.
There isn't a specific series of lenses. The KA mount was introduced in 1983. Any Pentax lens after that date will almost certainly have the KA mount. These lenses have 'SMC Pentax-A' engraved on the lens near the front element, and have a green 'A' engraved on the aperture ring just beyond the highest number.