The UC design was created as a solution to an issue with Bolt Pens. This is version 2. Bolt Pens of the past have a protruding bolt that would get hung-up in/on your pants or shirt, or they would likely snag on something as you pulled it out of your bag.
By making the pen Oval I was able keep the bolt flushed with the body of the pen and only in the extended position would the bolt be slightly higher than the frame of the pen body. This slightly raised position of the bolt would allow easy purchase when retracting the writing point. Sleek and unobtrusive. 5.12 in long with a deep pocket clip in Zirconium, Titanium and Copper. REFILLS: Parker Standard