This is the 3rd TwoSun pen I have purchased and carried. The bolt action is fun and functional. The glass break maybe makes this more "Tactical" than some of their other pens. I've not tested it yet to see just how well it works. However, if I hold this pen in a self defense hold (pen tip down), I find that I really do not have a comfortable place to put my thumb. The pen is comfortable on the hand and writes well. The clip holds firmly but is tailored more for shirt pockets than thick jean pockets. The milling looks great! Since the body is Titanium I may anodize it using 9 volt batteries as shown on YouTube just to give it a little color. WMK sells the TS-PEN19 pen at a really great price, so I can experiment with many different colors.