Vintage Wollensak Rochester USA 1-inch Sunray 116 F1.85 lens for 8mm movie projector.   This was on a Keystone R-8 projector but may fit other models as well.  Diameter of the threaded portion of the barrel is 0.68".  Lens has some internal dust but is guaranteed to be usable.  This item is guaranteed to be as described but is otherwise sold with no returns.