I have had a Streamlight Nano clipped to my keychain for the past 8 months, and it has served me well. A few weeks ago I came across the UST Pico, and I had to try it out. Since both lights are targeting the same market, use the same batteries, are about the same price, and share many of the same stats, I thought the best review format for each would be a comparison with the other. Size and Shape--Advantage: Nano Both the Nano and the Pico are .5 inches in diameter at the head, and 1.5 inches from nose to tail. However, they are shaped differently. The Pico is a true cylinder, with no real difference in the diameter of the head vs. the body. The Nano's head flares out, with its body diameter about 3/8". The slim body and flared head of the Nano gives something for the thumb to push against and makes it a bit easier to direct the beam where you want it to go. Construction--Advantage: Draw Both lights are made from anodized aluminum with recessed bulbs. They are well constructed and appear ready to take some abuse. Both have knurled heads to give a better grip when twisting the lights on and off. ***UPDATE 12-29-2014*** Finish--Advantage: Draw Both come in anodized aluminum in a variety of colors. (Incidentally, your color choice will have a major impact on the price of either light.) If you intend to snap either the Nano or Pico to a coat zipper, it will probably stay looking new for some time. If, however, you intend to attach it to your keys like I did, expect the anodizing to wear rather quickly with plenty of scratches. This is purely a cosmetic issue and doesn't matter to me, but if it does to you, be aware that neither of these lights has an extremely tough finish. *** Battery Use--Advantage: Indeterminate I haven't tested these for myself, but Streamlight claims the Nano will operate for 8 hours on one set of batteries, while UST claims 15. It's hard for me to believe that UST has perfected its technology to the point that it can nearly double the runtime of the Nano. Maybe Streamlight is referring to usable light, and UST is referring to the until-it-goes-out-completely number. If the Nano was brighter or the Pico dimmer, these numbers would make more sense, but as you are about to read, that's not the case. Beam--Advantage: Draw Both the Nano and Pico list an output of 10 lumens. I can't tell any difference between the two in terms of brightness; both are extremely bright for their size. The throw of both lights is also equivalent. The Nano light is a bit more pure white, and the Pico is a bit more yellow. The shape of the Pico beam is a more uniform circle, and the Nano is a bit more oval-ish. Neither stands out for me as being substantially better. Let's say the uniformity of the Pico is cancelled out by the pure white beam of the Nano. ***UPDATE 11-23-2014*** Some questions and other reviews have prompted me to add the following: So how bright are the Nano and Pico lights, and what can and should they be used for? They are completely adequate, and sometimes too bright, for the following dark-environment activities: 1. Walking from your car to wherever you are going and back; from 0--20 feet, you'll easily identify anything you need to walk over or around. 2. Walking around your house without turning on the lights and waking up everyone else. 3. Finding something in a closet/purse/safe. 4. Reading (for me, too bright for this). 5. Signaling other hunters to organize drives or simply alert them to your presence. As another point of reference, I can go into my basement (which has white-painted walls) at night with only this light, and identify everything, be it 1 or 40 feet away. Dissatisfaction with the brightness of these lights is due to one of three things: 1. A defective light--I haven't experienced this. 2. Weak batteries--a situation that is easily remedied. 3. Unrealistic expectations--You shouldn't expect to use either of these lights for search and rescue operations, spotting deer, or spelunking. You won't use them to light paper on fire or to blind an onrushing attacker. There are many other larger, heavier, and more expensive lights on the market that can do all of these things--check out Surefire, Fenix, or high end offerings by Streamlight or one of the other dozen like minded manufacturers. The Pico and Nano are smaller than your pinkie and weigh less than half an ounce. Keep those facts in mind, and you will be VERY impressed at their light output. *** Operation--Advantage: PICO Both lights function the same way. Point the light away from you, and twist the rear portion of the light clockwise (or the head counterclockwise) to turn the light on, and the opposite to turn it off. However, there's a difference here too. The lights are split differently. The Pico's twist point is 1/8" from the front. Sandwich that narrow head between your fingers, and you have the rear 1.25 inches to grab and twist. On the other hand, the Nano's twist point is .75 inches from the head, plenty of length to get between your thumb and pointer finger. However, that leaves your other fingers with only a half inch to grab. Because of this, you may find your rear fingers also gripping the front portion, fighting your front ones, and therefore making the twist more difficult than it needs to be. It is not a huge deal, and both designs function, but for me, the Pico's design is a bit better. Battery Installation--Advantage: PICO LR41 batteries are tiny. Two of them would make a standard pencil eraser. To insert batteries in the Nano, the best way I've found is to stack them on the counter, take the Nano apart, then slide the barrel of the Nano over top of the batteries, tilt it and put my finger over the opening, then screw it back together. At every stage of the process, those tiny batteries may try to scatter every which way. On the other hand, the Pico comes with a plastic housing that you slide the batteries into. Once they are in there, you can shake it and they won't come out. You then slide the entire holder into the light, screw it back together, and you're good to go. You will be able to manage either system, and with a minimum 8 hour runtime, you won't be changing batteries often, so battery installation is not a make or break factor. But the Pico's system is definitely easier. Tendency Toward Self Destruction--Advantage: PICO Many reviewers have complained that the Nano has a tendency to unscrew itself and come apart. Taking a tip from another reviewer, I used some thread seal tape on the threads, and I have never had the Nano come apart on its own. Truth be told, both lights have the potential of coming apart on their own, and both would benefit from the use of some thread seal tape. The difference is that if the Pico comes apart, it will be in three pieces, with the batteries all together. If the Nano comes apart, it will be in six, with the batteries scattered. Less tiny pieces to find=advantage Pico. Snap Hook--Advantage: Draw Both feature heavy duty snap hooks that allow easy attachment to keys and zippers. The surfaces of the Nano's hook are a bit flatter, while the Pico's are more rounded. If they are not exactly identical in size, they are so close as to make the difference negligible. Price--Advantage: PICO This is always subject to change, but as of early October 2014 Amazon listings, the Nano goes for about 8-9 dollars and the Pico for about 6-9 dollars, with your color choice determining the exact price. There you have it. Unless I find in the future that the Pico does not share the Streamlight's durability, my keychain flashlight needs will be served by the Pico from now on. The price difference is reason enough, but the operation, promise of longer battery life, and ease of battery installation put it over the top. By no means is the Nano a bad product, and you shouldn't be upset if you find yourself the recipient of one in the future. But if you're the one buying, I'd go with the Pico.
