For the ultimate in one-of-a-kind tritium glow fobs, look no further than the TEC Isotope Reactor. The Reactor Fob is designed to hold three glass tritium vials (not included) which will glow continuously for many years without the need to charge them from sunlight or UV light. The Reactor is configured to provide the highest visibility of mounted tritium vials than any other Isotope model we offer. The virtually unobstructed view of three 3mm x 23mm tritium vials in different colors gives off an amazing glow, and the vials are well protected by the Ti-6Al-4V titanium construction and durable borosilicate glass window. The tritium vials are easy to install, and the design provides a simple way to remove the vials if you want to exchange them for different colors. In addition, O-rings are integrated at both ends of the glass window to provide a water resistant assembly. Please refer to the "Installation" tab for details. Locate your bags in that pitch-black hotel room, find your keys in the dark, or simply have the most unique glowing charm suspended from your car’s rear view mirror. Whether you use the Isotope Reactor as a functional zipper pull or to simply identify your gear, there are a multitude of uses that will look absolutely amazing. Isotope Reactor Fob Features: 3 tritium bores equally spaced around center spindle shaft Each bore can hold one 3mm x 23mm tritium vial Combine different colored tritium vials for a beautiful effect Ti-6Al-4V titanium spindle and cap Crystal clear, scratch resistant Borosilicate glass window Water resistant O-ring seal on both ends of glass window Bead blasted, uniform matte finish What you get: (1) TEC Isotope Reactor Fob Packaged with (5) rubber plugs for tritium vial containment (3 required plus 2 spares) (5) Glass window O-rings (3 required plus 2 spares) (2) Spindle groove O-rings (1 required plus 1 spare) (1) 11.1 mm [7/16"] diameter split ring for attachment to other items (2) glass windows (1 required plus 1 spare) Note: replacement glass windows are available here Important Note: Product DOES NOT include tritium vials