FA Limited
missing in action
Pentax lenses can be mounted on Canon bodies via adapter, but mounting on a full-frame body requires physically modifying the lens, or keeping the mirror locked up at all times. (Not sure if that is even possible on the 5d Mark II... I guess with live view enabled?)
http://www.pentaxforums.com/forums/pentax-slr-lens-discussion/29917-pentax-fa-limited-canon-5d.html