Friday, March 4, 2011



The LED light on my keyring is probably one of my most used keychain items.  I find a small flashlight comes in handy for those times you drop something in the car, or for opening the house door in the dark.

So obviously, I wanted to equip my wife with a keyring light as well.  Unfortunately she doesn't share my enthusiasm for flashlights and wasn't particularly interested.  If I had to subject her to having a keyring light, here conditions were; (a) it had to be something small and light weight (b) not too expensive (she doesn't want me to 'waste' money on something she doesn't appreciate).  Surprisingly she wasn't too concerned about aesthetics.

I've come across the streamlight nano in the past, and having seen a pink version, I thought this would be ideal.  She has since had it on her keyring for over a year now.


The elongated 'bell-shaped' streamlight nano is made from an aircraft-grade aluminum with an anodised finish.  The original streamlight nano comes in black, but since then, a pink and blue version have also come out.  $1 from the sale of the pink version goes towards the breast cancer research foundation, while the blue version goes towards 'concerns of police survivors' (C.O.P.S)

Streamlight nano, Modamag drake, DQG tiny 2/3AAA, Dealextreme 'fauxton'

There's no mention of what sort of annodisation the streamlight nano uses, it does not feel very thick and I doubt it is HAIII. From over a year of usage on my wife's keychain, it's developed some wear on the edges and corners of the flashlight.  I feel this is normal wear characteristics for annodised aluminium... it arguably adds character.

The streamlight nano is one of the smallest keychain lights around, measuring only 3.73cm in length, 1.3cm in diameter at the head and 1.09cm at the body.  It adds minimal weight to your keychain, weighing only 10 grams.

The light is rated as being weatherproof, so if you get a few splashes on it, it should be okay.  It has a small o-ring to help keep out moisture and dust.

The streamlight nano comes with a clip that makes it easy to attach and detach the light.  The pink and blue versions also come with a FOB that features the logo of the institution it supports.  If you want to minimise bulk and weight, you can take the FOB off.

Fob and clip attached to the streamlight nano


The streamlight nano contains a 5mm LED rated with a lifespan of 100,000 hours.  This 5mm LED provides around 10 lumens of light, which is enough for lighting up objects at short distances.  Unfortunately like a lot of other 5mm LEDs, there is a blue-purple tint to it's beam.  The beam is also quite 'ringy' and has a lot of artefacts.

Beam at ~5 metres

Beam at ~0.75 metres

5mm LEDs have their limitations, they can not provide a lot of lumens like the 'CREE' powered LEDs.  However, the 5mm LEDs are more resilent and do not need a lens to protect the LED.  The LED itself can focus the light, avoiding the need for a reflector.  Both these last two points, help to reduce the size and the cost of the flashlight.

According to the streamlight specifications, the nano is meant give 8 hours of 'usable' output.  However this output is not at a constant brightness.  The streamlight nano is direct driven, meaning as the voltage in the batteries drop, the brightness will also drop.   So if you notice the light seems less bright with time, you may consider changing to a fresh set of batteries.

4xLR41 button cells on the right

Streamlight advertise this light as running on 4xLR41 batteries.  LR41 batteries are alkaline button cell batteries, they can be bought fairly cheap from internet sources.  If you are willing to pay a premium, consider getting the SR41; the 'silver oxide' version of LR41.  Silver oxide coin cell batteries tend to have a higher capacity than the alkaline equivalent.  They also have a flatter discharge curve and are better at providing a constant voltage.  To simplify... in theory, the SR41 should not dim as quickly compared to using LR41 batteries.

Be aware there can be a difference between SR41W (also called '392') and SR41SW (also called '382').  The SR41SW are low drain while SR41W are high drain.  Flashlights would be better suited for the high drain version (SR41W/392). 

You should also be aware of fake silver oxide batteries!  Have a read here  and here.


One of the most common issues that people report with the streamlight nano, is the light has tendency to come apart by itself. The o-rings and threads provide little resistance to twisting, so it is not suprising to hear this happens. 

Some suggested solutions to this problem are:
-adding some telfon tape (the sort that is used in plumbing), around the threads of the light.  This creates more friction and resistance to turning.
-adding some sort of swivel to the keyring attachment.  This means when the light accidentally rotates, it will hopefully rotate at the swivel, rather than untwisting between the head and body.

Streamlight nano with teflon tape on the threads, example of some swivels, roll of teflon tape
I have read some complaints that the light is difficult to operate one-handed.  I guess this is one of the trade offs of having a very small 'twisty' flashlight.


If you are looking for something ultra small and lightweight, the streamlight nano is a good contender.  It's not the brightest light around, but it will do the job for short distance applications.  The pink colour would be popular with most of the female population... and maybe some of the male population to boot!  If you get a pink version, its nice to know that little bit of the money is going towards a good cause.


There are quite a few button cell/coin cell lights around, with varying degrees of price and quality.  Some that come to mind are:

- egear pico zipper lite - I would consider this the direct competitor to the streamlight nano.  It's slightly larger as it has a battery carrier.  The manufacturer reports a longer runtime than the nano.  Comes in a wider range of colours

- '2x2016 coin cell lights' - in this category are the photon 'micro' range, inova microlight and the cheapo 'fauxtons'. From this range of lights, the photon freedom stands out the most to me.  It has variable brightness control and beacon modes included.
(example of a pink 'fauxton'):


CASE MATERIAL: Machined aircraft-grade aluminum with anodized finish. LED available in white.
DIMENSIONS: Length: 1.47 in. (3.73 cm) Diameter: Head Diameter: 0.51 in. (1.30 cm)
Body Diameter: 0.43 in. (1.09 cm)
WEIGHT: 0.36 oz (10 grams)*
LIGHT SOURCE: 5mm white LED, impervious to shock with a 100,000 hour lifetime.
LIGHT OUTPUT: LED Rating: 10 Lumens typical. Parabolic shaped LED area optimizes beam performance.
ON/OFF: Rotating On/Off head switch.
RUN TIME: Up to 8 hours declining usable output.
BATTERY: Four (4) IEC-LR41 coin cells.
WARRANTY: Limited lifetime warranty.

COST:  $6-$10




  1. I like your review about the Streamlight Nano. I edc-ed my Fenix LD15 everyday. I bought my gf a keychain flashlight too, from GP, which runs on 1 single AAA battery. I'm considering something brighter (like from Surefire / Fenix) for her for her birthday. (:

  2. @ L-Vin

    If you like the AAA format and are after something pink, have you thought about the 4sevens preon1? There's a special limited edition pink preon, with proceeds going to breast cancer research. It can be found here:

  3. The pics don't do this thing justice, it's very bright when used inside, when I was first got it I was surprised something so small could be so powerful! I'm definitely thinking about getting the pink one for my lady :)

  4. @MWDP

    Yeah the nano can be very bright on a fresh set of batteries. You will find that brightness fades as the the batteries drain though, but it should still be bright enough for short distances. You should have a look at the egear pico lite as well. I've done a comparison of the pico lite vs the streamlight nano here:

  5. Came across your site by accident. I'm sure glad I did. How cool to find other people who are as fascinated with these things as I am. The key chains, nifty gadgets, knives. All cool. But nothing comes close to the flashlight. I could go on for hours (someday, I'd just like to hold a Surefire), but this is probably not the proper place for it.
    You just gained another follower. Now I need to find out why it's posting this as Unknown, and then I need to figure out how to get back here.

  6. You say SR41SW (also called '382').
    I believe it equals the 384, not 382

  7. Thanks for the suggestion on the egear pico lite! I'll check that out!