For approximately 3 years, I've been lucky enough to have a Zero Tolerance (ZT) 0010BLK "tactical pen" prototype. I received this before the official product announcement. It's definitely a prototype, as it's got some noticeable problems (both that I noticed, as well as the individual who built it). Some of these include minor spacing/tolerance issues, others are things like using carbon-steel tools for engraving, which leaves behind tooling dust to rust. Other things are a rather tight pocket clip, when compared to production models. There's also no knurling where the "finger grip" is. The interior of the barrel is also slightly smaller. The prototype also had some crummy Parker refill in it, which actually burst open relatively soon after I began using it. This was immediately replaced with a blue Fisher refill. Personally, using a pen with a $125 price tag (MSRP for production models) seemed crazy to me, at the time. So, naturally, I left it at home, and used it at my desk almost exclusively. I do a lot of handwriting at home, so this got me to really get used to it quite a bit - just not carrying it outside of my house. Up until recently... With the latest KAI factory sale, I stood in line for hours at the LE/FIRE/EMS/MIL entrance, and was rather disappointed when I got in. Sure, they had auto's this year (at not so good prices) but I did spot the ZT pen, this time in brown, at the sale. I sorted through several of them, found a decent one, and picked it up for $35. Other than some cheap kitchen knives for camping, that was about all I got. So far, I've been carrying the pen for a couple of weeks, daily, and heavily using it. It's a bit of a beefy pen, compared to what I've been used to carrying around (Fisher bullet) but I lost my Fisher, so this would have to do. I must say that I'm really impressed with it. There are some flaws, like having a hardcore cap that can be a little sluggish to get on and off sometimes, especially when compared to the Fisher bullet, but for such a large pen, it's great. It's a little odd thinking of the pen in a "tactical" manner, but I think it might I would treat it the same way I'd treat any other pen in my pocket, if the need for some sort of improvised weapon like that came up. The addition of the carbide glassbreaker is new, and pretty useful, but I would never use it, unless absolutely necessary, particularly since a replacement would run me $$$ (and they've just discontinued the pens). Some things to note about the 0100EB pens bought from the factory sale: - Bare pocket clip : no ZT marking or serial number - Bare top of cap : No "MADE IN OREGON" engraving - RITR cartridge : Comes with a black 37R Rite in the Rain refill - Some flaws : They're not perfect, and they have some sort of flaws - mine has a faint scratch around the main body - XXXX : If normal engravings are (or aren't) present, there will be four X's engraved somewhere on the pen, usually near the pocket clip mounting area. - Different Colors/Finishes : They all have different textures, coloring, and finishes. UPDATE: 20 DEC 2016: Found my Fisher Bullet Pen, and putting it back to use, although I've ordered a clip, with an idea to modify the pen for some sort of lanyard or placement in a leather case. UPDATE: 23 DEC 2016: Received another cartridge/refill from RITR (manufactured by Fisher) for the ZT pen, as the original cartridge felt quite gritty when writing on one side, and almost felt like it was abrading the paper.