Customer Reviews

Based on 2 reviews Write a review

TEC-S311T Isotope Tandem Fob


Bead Blasted Stainless Steel
Black Diamond Carbon

Product Details

IMPORTANT NOTE: This product DOES NOT include tritium vial

The unique & versatile TEC-S311T Isotope Tandem Fob is designed around the use of a glass tritium vial (not included), which will glow continuously for many years without needing to charge it from sunlight or UV light.  Similar to the TEC-S323 and TEC-S360 models, the shorter profile and dual split ring holes at each end of the Tandem Fob will add a subtle touch of luminous style to your keychain or it can give your favorite gear it's own special glow.

The Isotope Tandem is an economical way to add a functional glow to anything you attach it to.You can also change out the vial anytime you like for different glow colors. Use different colors to identify different pieces of gear!

Complete your EDC collection with the small, functional and stylish TEC-S311T Isotope Tandem Fob, which provides just the right amount of light for locating items in the dark. Clip it between a backpack zipper and flashlight. Try it out with a P-7 clip and your best pocket tool. Attach it between the pull chain and pull knob on a ceiling fan. Where will you clip yours?

TEC-S311T Isotope Tandem Fob Features:

  • Custom designed to hold a standard 3mm x 11mm tritium vial
  • Stainless steel housing
  • Bead blasted, uniform matte finish
  • Available in your choice of stainless steel finish or our exclusive Black Diamond Finish (see "Specifications" tab for details)
  • Smaller size than our other Isotope fobs

What you get:

  • (1) TEC-S311T Isotope Tandem Fob
  • (3) rubber plugs for tritium vial containment (1 required plus 2 spares)
  • (2) 11.1 mm [7/16"] diameter split rings for attachment to other items
  • Important Note: Product DOES NOT include tritium vial

The TEC-S311T Isotope Fob is a metal housing suitable for mounting a 3mm x 11mm glass tritium vial. It is bead blasted to a uniform matte finish, or also available in our exclusive Black Diamond Finish.

  • Material: Stainless Steel
  • Finish: Bead Blasted
  • Outside Diameter: 5.0 mm [0.197"]
  • Overall Length: 24.0 mm [0.95"]
  • Split Ring Hole Size: 3.0mm [0.118"]
  • Total Assembled Weight (without tritium vial): 2.4 grams [.085 oz]
  • Total Assembled Weight (with tritium vial): 2.5 grams [.09 oz]


Black Diamond Finish

TEC’s Black Diamond Finish is a proprietary, nano-composite microlayer, uniquely replicating diamond’s low friction, high hardness and superb corrosion resistance. Genuine TEC products with Black Diamond Finish provide an extremely durable, near-black coating that offers exceptional wear resistance – Fine Personal Accessories for Practical Obsessions.

The TEC Isotope Fob Series are keychain fobs specifically designed to mount standard 3mm x 23mm and/or 3mm x 11mm self-luminous tritium vials. They do not include tritium vials, you must purchase them from another source typically outside the United States.

Learn more about what tritium is and where to buy it by clicking here.


  • Warranty

  • Shipping Times

View More

Sites Featured By: