The Vivitar is a K mount manual focus. Unusual in that as you focus it expands in both directions. I paid somwhere around $120 plus $12 shipping as new old stock a couple years ago. I have seen them from $120 to $170. Have not looked lately. The picture I took of it was with a new old combination. Pentax K100D with F, SMC, 50mm, 1.7. Pentax first version of autofocus. I think that is real sharp lens.