TEC-S323 Isotope Fob, a stainless steel housing for tritium vials - by TEC Accessories Custom-machined, stainless steel construction Find your keys in the dark without the need for charging or batteries Pairs great with other TEC Accessories gear Great for Everyday Carry enthusiasts Holds a self-luminous tritium vial (NOT INCLUDED) Custom designed to hold a standard 3mm x23mm tritium vial (sometimes specified as 3mm x 22.5mm) Bead blasted, uniform matte finish Available inyour choice ofstainless steel finish or our exclusive Black Diamond Finish Smaller size than our standard glow fobs (1) TEC-S323 Isotope Fob (3) Rubber plugs for tritium vial containment (1 required plus 2 spares) (1) 11.1 mm [7/16&#034;] diameter split ring for attachment to other items Important Note: Product <span class="a-text-bold">DOES NOT</span> include tritium vial Material: Stainless Steel Outside Diameter: 5.0 mm [0.197&#034;] Overall Length: 31.5 mm [1.24&#034;] Split Ring Hole Size: 3.0mm [0.118&#034;] Total Assembled Weight (without tritium vial): 1.8 grams [.06 oz] Total Assembled Weight (with tritium vial): 2.0 grams [.07 oz] Important Note: Product does not include tritium vial