Some sources say there are two versions, but for all practical versions, there is only one.
The prototype has a separate lens hood and an optional small economical 160mm protective optical flat. Pictured is the production AIS version, with built in retractable hood, drop in 52mm filters and a permanently mounted 160mm optical flat protective filter. The right hand shot shows no lens hood mounted. Also included are side mounted strap lugs for the ever convenient hand held shot. Close focus is 13 feet or 4 meters.