Item arrive in standard brown envelope. The light itself is packaged in an attractive metal box with a plastic window.

The head houses a P4 emitter, textured reflector and a multi-level IC controlled circuit. It's coated in a dark gray Type 3 anodizing with a band of diamond textured knurling about 0.5cm wide. The knurling really does well in providing grip for one-handed operation. The coating is very nice, very smooth and consistent, it's color also perfectly matches the tone of the battery tube. As you can see from the image to the right, the emitter is every so slightly misaligned to the reflector. Just about a hair's width. An orange rubber o-ring sits between the lens and reflector for waterproofing. The lens is advertised ad being AR coated glass, but from my observation of the outer surface of the lens, it doesn't seem to be so. I could be wrong though. Perhaps the inner side of the lens is AR coated, however the entire head module is sealed and I'm unable to verify this. The head already has a foam ring applied to the bottom to prevent battery rattle. At the bottom of the head module, a cosmetic silver ring shows between the head and the battery tube.

As with the head, the Type 3 coating on the battery tube is flawless. Most of the battery tube's surface is covered in diamond textured knurling. There're 3 flat faces machined onto it, and 3 horizontal slots running the tube's length, each about 1mm wide. If you are able to get a hold of some tritium vials about the same width, they could probably be glued into these slots. The threads on my sample is slightly rough, like the first run of the C-LE. There's also some machining dust left over between the threads which caused some grinding during initial use. A cleaning with a stiff brush will fix this. See the image in the gallery below, I cleaned the top 2 lines of threading and left the rest un cleaned to show the difference. There is some slight play between the threading of the head and battery tube, but luckily the thick rubber o-ring provides good tension and resistance. The insides of the battery tube is nice and clean, there's no spring inside for the "-" contact as suggested by the site's images. This means that there will be noticeable battery rattle if you loosen the head too much. At the end of the tube there's a single eye for the key ring attachment. The wedges cut into the base were not smoothed out and still show some machining marks, coating is fine though. The JET-μ can stand on it's tail end without any problem, but because of it's light weight, it topples over quite easily.

The beam profile of the of the JET-μ is a wide spot and has a smooth transition from hotspot to spill beam. The spill beam is very subtle, and at more than 1m this light makes a very good flood beam. The tint on my sample is a slightly cool blue around the edges of the spot. After scrutinizing the beam profile I did notice that one corner of the spot is just slightly darker than the rest. I suspect this is caused by the slightly misaligned reflector. I have to stress that the difference of this dark area is almost unnoticeable under normal use. Look at the control shot on high mode for reference, the dark area is at the top right corner of the shot.

The efficiency of the JET-μ's circuit is average at best. Let's compare this to the closest other light in it's class, the Fenix L0D CE. The spot of the L0D CE is about 300% brighter and runtime is about 60% longer than the JET-μ, both on medium mode. Granted the L0D CE has a medium spot while the JET-μ is more flood. Ultimately it's up to you, weather you want to sacrifice the runtime of the L0D CE in exchange for the flood beam profile of the JET-μ. Medium and low levels are controlled by PWM. Pulses are unnoticeable unless you intentionally look into the head while waving it around. To switch between modes, simply turn the light off and on within 1 second. A nice feature about the JET-μ is it's memory function. Keeping the light on for more than 1 second in any of the modes will keep it in memory, so it will be in the same mode the next time it's turned on.

The operating modes are:
Off >Medium > Low > High > Strobe > Beacon

I did not do runtime tests on 10440 cells because of heat issues. Running on 10440 should be limited to less than 1 minute as per manufacturer's advice. The runtimes posted on their site on running 10440 cells were calculated from current draw, not practical testing. Take note that I have only posted a control shot for the high mode because the PWM used for low and medium, much like with the C-LE, isn't represented accurately with my camera.

Runtime 1x AAA 800mAh Eneloop Medium 01:46 to 50% Low 04:03 to 50% High 00:48 to 50%

The Good - Type 3 anodizing is perfect and the generous amount of knurling provides excellent grip. Single-handed operation of the twist switch poses no trouble. Very smooth and wide spill beam. The higher frequency PWM used works much better than the original C-LE.

The Bad - Threading has some machining dust left over which causes some grinding, and there's also some play between the threads of the head and battery tube. Usage of 10440 limited to less than 1 minute at a time due to heat issues.

The Relative - Memory function enables the light to turn on on the last mode used. Uses twist action for on instead of a push button switch. Body design is generally nicer than other current single AAA lights available.

Here's a video of all the modes and the effect this light's PWM has on my camera.

Package.

Package (inside).

Head module (front view).

Head module (side view).

Head module (rear view).

Battery tube (front view).

Battery tube (side view).

Battery tube (rear view).