Microtech Kyroh Pen in titanium with Fisher Space cartridge and tritium insert.

Just a close up of the Kyroh pen in Satin finish.
You can buy directly from microtechgear.com
Spec:
The Kyroh is a bolt-action pen that twists and locks into place and accepts replaceable Fisher Space cartridges. Coming in both standard and mini sizes, the pen is fashioned with a textured grip, glass breaker, sturdy pocket clip and replaceable Fisher Space ink cartridge. The Kyroh is sure to be a solid addition to your everyday carry. Available in bead blast and shot-peened finish.
Pen Material: 6AL-4V
Small Length: 4.8”
Large Length: 5.87”
Barrel Diameter .5”
Weight: 1.8 oz. / 1.4 oz. (Small)