Saturday, May 17, 2014

TEC-S323 Isotope Fob Review

TEC-S323 Isotope Fob Review

With the recent addition of the diminutive “DQG spy” to my current keychain setup, I've been finding my usual Tec Accessories S3 glow fob, a little too large in comparison.  Looking around for a smaller alternative that is still encased in metal, brought me to the TEC-S323 Isotope Fob, also made by Tec Accessories.

I've been out of the loop with these sorts of things, but the TEC-S323 Isotope Fob appears to have been released around a year ago.  It is a metal housing built to hold a 3x23 tritium vial.  The dimensions of the Tec Accessories Isotope promise to be slightly smaller, thinner and lighter than the TEC-S3/A3/T3 glow fobs.


(Taken from the manufacturers website)
Material: Stainless Steel
Finish: Bead Blasted
Outside Diameter: 5.0 mm [0.197"]
Overall Length: 31.5 mm [1.24"]
Split Ring Hole Size: 3.0mm [0.118"]
Total Assembled Weight (without tritium vial): 1.8 grams [.06 oz]
Total Assembled Weight (with tritium vial): 2.0 grams [.07 oz]
Cost: $23 (not including the tritium)

Packaging and Accessories:

The packaging is pretty plain from the Tec Accessories.  Everything comes in a ziplock bag.  Included is a small container with a small split ring and 3 rubber plugs.  You only need one plug for the installation of the tritium, so the others are spares.  Another small cylindrical plastic container holds the metal housing and keeps it safe whilst in transit.  A card with basic instructions is included.

Please note that the tritium vial is not actually included, if purchased directly from Tec Accessories.  You need to buy the 3x23mm tritium separately, or alternatively Merkava from cpfmarketplace sells the Isotope preinstalled with the tritium.  Merkava is one of my regular sources for tritium, but there are a few others also on cpfmarketplace forums.




Pretty simple to put it together... no need to mess around with any glue or adhesives.  Put the 3x23 tritium vial into the metal housing. GENTLY ease one of the rubber plugs on top of the tritium.  Place split ring through the appropriate hole.  I tend to use a pair of fine pliers to open the split ring.  With the rubber plug and the split ring in place, the tritium vial is very unlikely to ever come out by itself.


-Smaller than the TEC A3/S3/T3 glow fobs
-Simple to install
-Feels well made
-It's subjective, but I like how it looks
-Once again subjective, but I think tritium in a metal housing looks more classy than a plain plastic tube
-Reasonably priced compared to other custom metal housings


-Not covered by a plastic shell, like the TEC S3/A3/T3.  This means it's smaller, but also potentially less protected if something hits it through one of the gaps in the metal housing.  However as of this stage, google does not find any reports of broken tritium in the Isotope
-Even though the TEC “Isotope” has been designed to maximise visibility, I feel that the tritium is slightly more visible in the TEC S3/A3/T3.  I feels this is the case, because the plastic shell provides more “spacing” from the tritium to the metal housing.
-Tritium definitely not as visible when compared to a plain acrylic housing.

Nite Glowring, tritium in acrylic casing, Tec S3 Glow Fob, Tec Isotope Fob, DQG Spy


I suspect the Tec Isotope Fob will be a permanent addition to my current keychain.  I like how it looks, and the smaller size better suits my keyring setup.  My only possible concern is whether the housing provides enough protection for the tritium.  It would take a very unfortunate knock to break the tritium, though.  I guess we'll find out with time and usage...

My keyring setup

Wife's keyring


Information on tritium and TEC Isotope Fob:

Manufacturer's Webpage:

Forums to buy 3x23 tritium and preinstalled Isotope:


  1. Hi how much for the S3 glow fob please ?
    The smaller one or second one in the picture.Is it covered by hard resin platic, like the first one? Is the liquid amount same size as the rest.Im in Australia also.

  2. Opps, i buggered up, im after the smaller acrylic cover one, the 2nd one in the pic, how much please?

  3. Hi Diane, I don't know if the guy still does the acrylic cover. It's
    a bit more complicated to do, as you need to buy the acrylic tube,
    tritium and special glue separately, and put it together yourself.

    I've had the Tec isotope glow fob on my keyring for a couple of years
    now with no problems. There is an updated version tec isotope 360.

    You can buy it preinstalled all ready to go from this thread:

  4. sadly i had to say that i lost 2 vials within one month on my keychain. they are not very stiff during normal use. if you carefully try to bend them you will recognize a lot flex.

  5. Interesting to hear about your experience enshiro. I don't try to flex the tritium vials, but I've had one on my keychain and one on my wife's keychain, since I did the review. Haven't had an issue with either. But to be honest, we don't subject the keychain to a lot of abuse either. My just sits in my pocket most the time, and wife's sits in her handbag.

  6. This is so cool a gadget serving dual purpose of a key chain as well as glowing in the night time which illuminates the dark nights. Thanks for update.

  7. Personalized Name Keychains I am thankful to you for sharing this awesome article. Gorgeous pictures of the keychains.