An ideal EDC pen for many reasons. I'm a pen guy who uses a pen professionally for field work. Also, given COVID-19, it's smarter for one to always carry their own pen as part of their EDC gear. I'm quite specific about an ideal pen for these reasons and the NTP31 is among the best I've come across for the reasons below.

First, the pen has a full metal construction. No inner plastic parts found that can break over time from stress wear. The pen is also made of anodized aluminum just like Nitecore's flashlights making this pen durable and corrosion-resistant. Due to the aluminum alloy construction, the pen is very lightweight and the slim form factor allows it to fit into a pocket nicely for EDC. I don't feel it in my pocket when I carry it which is ideal. The weight and profile is similar to a Parker Jotter which is a world favorite for decades.

The bolt action is functional but not the smoothest out there. I blame the anodization of the internal components which don't have a low friction coefficient. Some bicycle chain oil helped but this action won't be as smooth as bare metal actions with a bit of lube. This bolt action is designed for function and not for fidgety play for a satisfying feel. The dual bolt action design is brilliant. This allows one to hide the tungsten glass breaker to make this pen low-profile and less likely to damage, injure, scratch, and snag on things unintentionally. You simply deploy the glass breaker when you need it with a bolt action deployment much like the pen tip. It's very smart. The glass breaker itself is on the dull side compared to another tactical pen I own but I trust it will do the job if needed.

The German-made gel refill is high quality and writes well whether single sheet or on a notepad. I've swapped it out for a Uni Jetstream high output ballpoint refill which fits and works very nicely in the NTP31. The pen takes different kinds of refills in the G2 form factor so one can swap out between gel and ballpoint refills as desired.

The clip is on the firm side. It doesn't flex very much and is bolted on very well. The good thing is that this pen is not likely to move around or slide out due to this very secure clip. The down side is that it will take a bit more effort to remove and clip the pen back into a pocket.

The price is also right, giving one everything you'd want in a well-made EDC tactical pen of a discreet, low-profile design. The anodized aluminum construction is a very enticing alternative to pricey titanium pens that cost 5 times as much. Nitecore's own NTP30 is the exact same design but in titanium for literally 5 times the cost of this NTP31. Maybe something for the collector but for the field carry professional or EDC, this is the better piece of gear for your money.

Writes well
Easy to carry
A little stiff bolt action going from pen to glass breaker.