this auction is an original Pentax K?  Mount  300mm F4 Telephoto lens.

new old stock, never used. leather case and packaging, though papers are missing, glass is perfect
Lens is marked: SMC Pentax 1:4 300mm Asahi Opt.Co. Japan.

it comes with a box that might be for a different version of such lenses, which shows a green star. so please focus on the lens pics. 

US continental only, buyers with at least 10 positive reviews..