IMPORTANT NOTE: This product DOES NOT include tritium vials. Please refer to our Tritium Primer to learn more about tritium and where to purchase it. If you are looking for a tritium glow fob with a head-turning wow factor, you have just found it. Introducing the TEC Isotope Photon. The Photon fob combines a number of unique design features to make it the most advanced tritium lantern available. The Isotope Photon is designed to hold one single 3mm x 23mm glass tritium vial (not included) which will glow continuously for many years without the need to charge it from sunlight or UV light. When viewed through the three large windows in the housing, you get an almost unobstructed view of the tritium vial. It is suspended by the end caps of the internal glass cell, looking similar to a radioactive fuel rod in a science fiction movie. The impressive feature list starts with a grade 5 titanium housing, which allows the fob to withstand an abundance of abuse and still keep glowing. But it's not just the housing that makes it so durable. The internal cell which supports the customer-supplied tritium vial cushions each end with o-rings to reduce potential shock. In addition, the entire tritium cell assembly is spring-loaded into the housing to further enhance the shock absorbing capability. What about the glass tube? Manufactured from durable Borosilicate glass, it is further protected by the housing with the three viewing window frames. Tritium installation is extremely easy, with no requirements for tools. Simply unscrew the tail cap, remove the tritium cell, and remove one end plug. Drop in the tritium vial and replace the end plug, cell assembly and tail cap. That's it. If you decide to change out the tritium vial at a later time for a different color, it's a one minute job. 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 Photon as a functional zipper pull or to simply identify your gear, there are a multitude of uses that will look absolutely amazing. Isotope Photon Fob Features: Accepts one 3mm x 23mm tritium vial (sometimes specified as 3mm x 22.5 mm) Ti-6Al-4V titanium housing construction Spring-loaded shock-absorbing design Crystal clear, scratch resistant Borosilicate glass tube Water resistant o-ring seal on both ends of glass tube Bead blasted, uniform matte finish No-tool tritium installation What you get: (1) TEC Isotope Photon Fob (1) Spare o-ring for tail cap (2) Spare o-rings for glass cell tube (1) 11.1 mm [7/16"] diameter split ring for attachment to other items Note: replacement glass windows are available here Important Note: Product DOES NOT include tritium vial Specifications The TEC Isotope Photon Fob is a titanium housing with a glass window suitable for mounting a single glass tritium vial. Housing Material: Ti-6Al-4V Titanium Finish: Bead Blasted Glass Window: Borosilicate Glass Outside Diameter: 11.0 mm [0.433"] Overall Length: 64.5 mm [2.54"] Split Ring Hole Size: 3.0 mm [0.118"] Total Assembled Weight (without tritium vial): 10.7 grams [0.377 oz] Total Assembled Weight for (with tritium vial): 10.9 grams [0.381 oz] *Does not contain tritium vials Borosilicate Glass:Although we have integrated a glass window in this product and is therefore susceptible to breakage, we use a very high quality Borosilicate glass. This is similar to the more familiar brand name Pyrex, and is extremely durable against thermal stress and shock. It is also scratch resistant and provides a crystal clear view of the tritium vial. We have performed 5' high drop tests of the Photon assembly onto a hard concrete surface without glass breakage. However please bear in mind that this does not guarantee it will always survive such a fall, or that the installed tritium vial will survive such shock so please consider this in your application. Extra replacement glass windows are available here Tritium Vials The TEC Isotope Photon Fob is a keychain fob specifically designed to mount standard 3mm x 23mm self-luminous tritium vial. It does not include a tritium vial, you must purchase one from another source typically outside the United States. Learn more about what tritium is and where to buy it by clicking here. Installation Install the tritium vial and assemble per the instructions below: Installation Instructions: Remove the Photon assembly from the foam packaging. NOTE: The end cap is not fully installed to make removal easier. Remove the end cap. Note that the cell assembly is under spring pressure, so be careful it does not pop out of the housing. Remove the cell assembly from the housing. NOTE: There is an unretained compression spring located behind the cell assembly, make sure it does not fall out. If it does, simply place it back inside the bore. Remove one end cap from the cell assembly. Install the tritium vial into the glass tube, making sure the end drops into the hole in the opposing end cap. Reinstall the top end cap. Insert the cell assembly back into the bore against the compression spring. Thread the end cap back into the housing. The installation is now complete.