If a pen is an absolute must for your everyday carry, you could do far worse than this one from Machine Era. Machined in-house from solid brass, this American made pen is reliable, tough, and will age beautifully over time. The cap is threaded for extra security and can be screwed onto the back of the pen when in use. It's also compatible with Pilot G2 and all standard Uni-ball cartridges, so you can use your ink of choice. And at just 4.6 inches in length and weighing only 1.6 ounces, it's the perfect size to keep in your pocket.