It's bright, flashes, waterproof it seems, and as for the sizing complaints, it seems easy enough. My dog is a larger-medium sized dog (50 lbs) and a medium fits her fine. I leave her leather collar on for leashing. This way the light-up collar does not have to be too snug.

Only downside: if your pup has medium or longer length hair, it may cover most of the collar which makes it tough to see. I bought a medium for my 50 lb. Aussie and it's extended at full length, but fits nice and loose. I bought a large for her Berner buddy and it fits him with room to spare. Only other notes: it's easy to use, but the D-ring knocks against the plastic buckle when she runs and makes an audible knocking sound. If you pup is noise sensitive, a piece of cloth tape wrapped around the apex of the D-ring may help.

The rubber tubing will go threw the adjustable part so you can make it light up the whole collar. Someone said that the collar was only lighting up half, because of them having to size it. If you read the instructions it will show u this. & yes the collar is BIG. I have a 85lb lab and got a Lg & it fit him but I think I will order a Med this time. The collar has been great! My dog swims with it all the time and I have had it for about 6wks & it still works fine. The collar gets dirty and makes it hard to see the light but I just wash it and its good as new. The only reason Im getting another one is because so many of our friends want them so Im stocking up to hand out so they can all be seen and safe.

This collar is great!! It is very waterproof and durable. We go camping almost every weekend and our black lab swims and runs around in the woods and it has held up great! We can always see him. The one thing that I have noticed is that the collar gets a little loose after a few days of wearing it? has anyone else had this happen? I may need a smaller size? I bought a Large for my 78lb Lab. He is only 1 1/2yrs old so I might need a Medium they seem to run Large. Get this if you have a hard time finding your dog at night. It has truly saved his life a few times.

Our black lab mix disappears in the dark. This collar gives us a way to know where he is. So, we love it. We haven't had it for very long, though -- only about 2 months -- and the light is getting dim. We haven't used it for very many hours. I wonder where they came up with that '100,000 hr LED life' statement in the description! Thankfully, the battery is replaceable. I hope when we get a new battery, then the collar will be bright again.

After reading all the raving reviews, I went ahead and bought this collar in a large size since my dog was right on the border between med and large. The collar is definitly very big.

My main complaint is that the collar is not quite as bright as I thought it would be. There is a single LED that shoots into a clear, rubber strip, thus illuminating the red strip (like a fiber optic). The major problem was that with the large size, the LED is not quite strong enough to light up the whole rubber strip. I ended up cutting off half of the rubber, so only half of the collar is actually lit up.

Other than that, a pretty nice safety feature for any dog that plays in the dark. I'd say, it does its job, but I can dream up a more spectacular product using multiple LEDs.

Great company (Backcountry.com) and great product. My lab loves it. We run at night on the coast of Northern California and when the LED collar comes out he goes nuts and gets ready for his run.

The collar works well and has a good light. My dog has a very short rusty red coat and completely disappears in the park at night. This collar is just what we needed.
I wish there were more sizes; my dog is at the smaller end of 'large' and by the time the collar is adjusted, only half of it lights up. I can see where she is unless she's standing just the wrong way, but as soon as I call her and she moves, then the light shows again.

I take my dogs running in the dark in the morning and also camping. This is the single best dog light you could buy.

Clip on dog lights tend to move around on the collar and can get 'lost' in dog fur. And the blinking of regular dog lights can get annoying (for me). This collar is so easy to see and the dogs don't mind it at all.

The last time we went camping on a moonless night, our dogs went swimming with these collars on (no problem with water) and our friend's dogs had clip-on lights -- that got lost.

My dogs weigh 80 pounds each and I got them the large. It fits a little loose, but I leave on their regular collars with tags and just add this one.

Works great- My dog is completely black so we use this collar on our camping trips, so we can keep an eye on him. Always gets lots of complements too! Ran true to size, and we've used on multiple trips and the battery is still going strong. Would highly recommend!

this collar works great, you can see it from a ways away. not very heavy and the whole collar lights up. just be careful because the small is VERY small. might want to go one size bigger than you think. : )

We take our dogs down to the beach on an island where they can run off leash, including at night. I have been using a blinking light that hangs like a collar tag, and that works fine. However, I loved this collar for the much better 360-degree visibility. I just wish that they made smaller sizes. Be warned - the small size was very nearly too big for my "big" (12 lb. - 12" at shoulder) dog.

This collar is just what I needed. I used to tie glow sticks and other lights to my dogs collar that would only show their position at certain angles. With this collar my 70 lb dog is easily identified at almost any distance. She doesn't mind the collar and enjoys being able to run at night instead of having to sit by my side by the fire. Awesome idea!

This collar is awesome! Its great for those winter walks (when its completely dark by 4pm)after I get home from work. Its perfect!

I can't say enough good things about this collar. For an owner whose dog loves to run around and chase everything in the night, it's good to have the self assurance that you will always be able to spot him. Fits perfect and the light has always turned on. Much better than a clip on.

I followed the sizing chart and the collars I ended up ordering were too big. couldn't return them since I already took the tags off and put them on my dogs while up camping. Should have ordered a size smaller. Sizing chart is not true.