Tritium Glowrings


First produced several years ago, Glowrings were, and still are, marketed as the “ultimate glow-in-the-dark keyrings”. They are unlike any other glow-in-the-dark keyrings in as much as they glow constantly right from the point of manufacture, for over 12 years, needing no recharging or exposure to light. The glow comes from the energy released by gaseous tritium – a mildly radioactive gas sealed within small glass tubes inside the plastic bodies. The tubes are coated inside with coloured phosphors which are stimulated by the radioactive emmission and cause a mild glow. By day they look like nothing special, but after dark they come into their own. The colourful glow each one emits is faint but very noticeable in complete darkness, and as such make them ideal not just for key-finders, but to locate just about anything that you might need to find at night-time. Door handles, light switches, pull-cords, zippers, torches – the list goes on. Now I know what you`re thinking – radioactive?!! Yes it is true, but the amount of radioactive energy released by the tiny volume of tritium gas in each glow-tube is so small as to be completely harmless. The radiation cannot penetrate the glass tube walls or the plastic keyring bodies. Should the tubes break, the gas would dissipate into the air in seconds, posing no serious risk at all.


Cost- New-style GB£6 each, X2 style £10 (from AdventureKit). Less if bought in quantity.

Size- Old style, 48mm long (1-7/8 inch) x 10mm accross (3/8 inch).
Size- New style, 53mm long (2-1/16 inch) x 14mm accross (9/16 inch) at the widest point.
Size- X2 style, 49mm long (1-15/16 inch) x 12mm accross (7/16 inch).
Light Source- Sealed glass vial containing Gaseous Tritium, with internal coloured phosphor coating.
Colours avaliable- Green, yellow, ice-blue, dark-blue, orange, pink. X2 version only green, blue or pink. Old style was not made in pink.
Body colours/finishes- Old and new style, clear. X2 either black or silver ends with body colours to match the glow tube.
Batteries- N/A. Glows constantly for over 12 years.
Switch type- N/A. Cannot be turned off.
Waterproof?- As good as.
Approximate beam half-angle- N/A. Visible 360 degrees around.
Peak Beam Intensity- N/A.

Notes- Beam Quality rating related to the brightness, visibility and colouration. Battery Life rating based on the overall predicted lifetime (I don`t have the time to conduct a 12 year run-time test!). Old-style Glowrings are not produced any more and are not taken into account for the ratings. They are presented here only as a guide, as the life of the product is so long that old-stock ones may still be avaliable.
International avaliability depends on the law of your country regarding the use of radioactive tritium light sources. In the UK they are perfectly legal, however in the USA they are not legal to sell, being classified only as novelty items.

Beam Profiles.

The first thing I should mention about Glowrings is the brightness. Do not expect them to shine like highway flares, and please don`t let the photos above mislead you. The light emmitted by the tritium tube inside each Glowring is very small indeed. They are not bright enough to read by or see with, they are designed just as markers. I would reccomend that if you buy some of these for the first time, when the package arrives do not open it until night-time, otherwise you could be quite dissapointed. I made the mistake of tearing open my first shipment of these in broad daylight, saw three card-top bags with little clear plastic keyrings inside and wondered what I`d just spent my money on.


Come nightfall it became apparent – it needs to be almost completely dark in order for the light to stand out., but stand out they do! With night-adjusted eyes, the colourful glow is extremely visible to me. Out of all the colours, the green one seems the brightest – that could be due to the fact that the human eye is most sensitive to green light. Next is light-blue, yellow and orange. Dark blue is dimmer but the deep colour is still rather eye-catching – some people call this one purple but it certainly isn`t purple to me. The new pink ones seem the dimmest, and are not a strong shade of pink either. It appears more lavendar colour, and the photo above is a pretty good representation. Still, the difference in brightness is not huge, and they should all be visible to most people after dark even at distances of over 20 feet.

Original Glowrings

The original, and in my opinion, best of the Glowrings. These are a little smaller than their more recent replacements and have a square cross-section profile. Moulded from thick clear acrylic-type plastic they are just about indestructable, if it wasn`t for the fact that the light source inside is a glass tube. Everyday handling that an ordinary keyring would go through won`t be a problem. They are durable enough to shrug off shocks, and are supported at one end with a blob of silicone that not only seals the tube inside but also provides some cushioning. They are not completely unbreakable though – I had one of these attached to a large bunch of keys which got dropped from quite high up, shattering the tube inside. Admittedly it was about 15 feet up in the air, enough to damage most glass products.
The originals came in just four of the six colours avaliable today, with a limited-edition orange one made in small amounts, which I think was a Halloween special. They are quite hard to find today. Pink is a recent addition to the range, and as such the originals were never made in this colour. Old-style glowrings are no longer produced, and are presented here only for information and comparison purposes.


New-style Glowrings

A couple of years ago the original Glowrings were updated. Personally I don`t think the new style ones are an improvement over the originals, but many people seem to prefer the smoother profile. They are longer and take on an overall teardrop-shape, with the Tritium glow tube occupying less than half of the overall length. One advantage of the new design is a magnifying effect produced by the curved shape, which serves to enhance the appearence of the glow from certain angles and does make them a bit more visible than the old style – this is noticeable in the photo further up the page. I have not had much of an opportunity to durability-test the new design yet. It does seem more fragile than the originals – the plastic portion through which the split-ring attachment is thinner, and the construction is in two halves that are just pressed together. Additionally the glow-tube is not secured or cushioned in any way, it sits loosely held into moulded grooves in each half and can be heard rattling about when shaken. I suspect a drop could damage it rather easilly, and there is a chance that over time the two halves could weaken and eventually become seperated, freeing the glass vial from within.


X2 Glowrings

These are the latest design to hit the market and currently are only avaliable in green, pink and blue. They improve not only on appearence but also slightly on brightness too. The construction is of turned aluminum end pieces and a dayglo-coloured plastic center tube that is very eye-catching by day as well as night. I think my green one looks a bit like a little version of one of Homer Simpson`s plutonium rods! The tube has thick walls and is very tough, protecting the Tritium glow vial inside. The vials in X2 Glowrings are the same length as the normal ones, but are thicker and a little bit brighter. Next to an original green one there isn`t a huge difference, but to me it seems more visible at a longer distance.

Though they look tough, I have a serious problem with my green X2 unit that was apparent right from the moment I first handled it. The aluminum end pieces are held in place only with glue, and it seems the glue holding the top cap on this particular one wasn`t strong enough, or wasn`t applied thickly enough. The result is the fact that the body seperates from the top all too easilly. If I were to attach this to my keys, the body would become detached very quickly. What is more concerning is that with the top cap removed, the glass vial of tritium gas can drop right out and could get broken easilly. I have heard reports from others of end caps detaching, and in reality it is not a problem that is hard to fix – a dab of decent superglue will stick them right back together. If yours fails in this way and you don`t have any glue on hand, the manufacturer`s guarantee should cover the breakage and allow an exchange for one that isn`t so loose. I also expect they are aware of this problem and are taking steps to prevent it. In the future I`ll obtain another X2 Glowring to see if it is any stronger than this original one.