Pentax K-mount auto focus full frame fish-eye zoom. F3.5-4.5. For exclusive use with PENTAX Digital SLRs. Like new condition. It's the one lens I've never had to pull back away from a subject with ! I have really enjoyed this versitile ultra wide lens. Everything from street photography to landscape to automotive and architecture - once you master it's unique 180 degree perspective you'll be addicted. Amaze your friends! 3 attached photos were taken with this lens.