Small, great for keychains, bright enough.
919712
Great small size, and the light is bright enough to see where you are stepping in the dark. I will use it to walk at night in the farm, so it is easy to carry in my keychain. It is not as bright as a regular flashlight, but it will help you finding items or candles in your house or basement if there is energy shutdown.
2165877
Great small Keychain light. This AAA battery powered light is surprisingly bright!! I'll be buying several more as gifts
4403814
I've bought 3 or 4 of these great little lights over the last ten or so years since they were introduced. Not the latest or greatest in brightness, but a durable, high quality long running and long lasting little keychain light.
1859190
I am rather impressed by the brightness of this tiny guy - it is brighter than my Mini Maglite that is powered by two AA batteries and is probably 10 times bigger. Along with my keys, I have this flashlight and a Verbatim Tuff 'N' Tiny flashdrive, and I feel as though I am well prepared and geared...

The size of this thing can not be beat. It is about 1.5 inches long - shorter than all of my keys and only about 0.5" in diameter. It is true that it is not designed to open with one hand - with a twist mechanism - but I am able to open it with one hand with some needed dexterity, though this is not an issue for me.

All in all, I would highly recommend this to anyone to put on their keychain. It is well worth the price!
1468434
Perfect keychain flashlight! The light is about the size of a house key, and weighs almost nothing.

Wish I had heard about these sooner, they would have made great stocking stuffers.
3160210
Great flashlight due to its brightness.  Very small. Fits on key chain or in pocket.  Very durable.
1549396
I bought 2 of these and will probably buy more soon. It is just under 2 1/2" long and 7/16" diameter. Smaller than my tiny Olight AAA but bigger than my Streamlight Nano. The picture in the description is misleading. It appears stubby but is actually much slimmer and sleeker. It also has a red accent ring near the tail. I'm a flashlight nut and have about 20 or 30 (afraid to count). I love this tiny light. The springy tail switch works well for momentary on, which is what this light is really meant for, due to the limited 45 minute runtime. However, you can push it fully and it will stay on if needed. It seems like a good switch and I don't foresee it turning on accidentally as being a problem, but I will update if needed.

The Amazon description says 33 Lumens, but the package says 18 Lumens. It is probably 18, which is pretty fine for a tiny light. It will light a path at night, just not too far ahead. The beam is not perfect, obviously, but not bad at all. It uses 4 AG5 batteries (included) which some may not like, but I bought 50 for 7 or 8 bucks, so I'm probably set for years.

I use flashlights often at work and elsewhere, so I also carry an AA light with rechargeable battery that I recharge often. I'm embarrassed to say it, but I often carry 3 small flashlights. I can't imagine this as my only light, so make sure it suits your needs. What the heck, buy it anyway, it's so darn cute and works well for just a few bucks. Perfect small gifts too.
2862349
I needed a small light for my keychain so I could actually see when I come home late at night, and this certainly was the perfect solution. It's insanely small (barely bigger than my house key), seems to be very durable, including the clip, and the light is extremely bright. I would definitely be interested in buying more of these for myself, family, and friends.
3368453
Very very small, like the descp said 1 inch, However, they are  bright. I like the fact that they come with plug & play extensions. There is no " last function " memory recall, you have to push 2 buttons to get the desired effect ( strobe pattern ) . I bought 2 sets so i can custom build what i want.
1158326
These are very bright and perfect size for key-chains. I have used this a few times and people are amazed at how much light it puts out.
4226918
Love how small this flashlight is and for its size,it works well. I like that there is no button I have to hold, just a twist and it stays on. So handy to keep on my keychain. I've ordered this multiple times and given them to family and friends. They not only appreciate it but tell me about the times it came to the rescue.
3899781
Very small and simple, cool as a keychain. However I used it in a project to make a starship in a bottle. I like to think it turned out well, but check out the picture to device yourself.
4939201
Small, bright and cheap! A great option for a second light, or for adding to your helmet or bag.
413526
These are bright little LED lights! I purchased the silver wire/warm white light set. The battery pack is small, slim, and super easy to conceal (house key size). The batteries included (button cell CR2032) are common and easy to find; I buy button cell batteries from the dollar store. I have lots of fairy lights/twinkle lights and these are perfectly acceptable. They're designed for small projects. My in-laws are hawaiian and during the holidays we like to light up pineapples with these lights.
2504363
This is tiny and perfect for a keychain, I like minimal and do not carry a lot of keys with me, I can barely see it sometimes from how small it is. with 3.0 you can't go wrong with this. very fast and solid metal.
1847992
Great bright little light which is perfect size for the key chains.  It is about as long as your keys. Wife loved the pink color and breast cancer logo.  Just twists to turn on/off.  Easy to operate nice and bright, have to see how long the battery lasts.  Seems very well built.
1931472
It's small but very bright, comes in handy when I'm with my AAA members at night.