Just remember to read the directions- you need to press it for ten seconds to get it off trial mode. After I figured that out, I think this is one of the coolest gizmos out there- a great thing to have on your keychain for extra durable light, and for attaching permanently to your bag when you're biking at night. Seems very durable too. You do have to press it firmly to get it on and off, but that better than a light that turns on by itself in my bag, and then is drained by the time I go home. Also, I don't have to worry about someone stealing it off my bike if it's in my bag...Great price for some extra light.

I like a bunch of products from this company but not this one. It's practically impossible to turn off or on, you have to squeeze it so hard. I sent it back and wouldn't recommend it to anyone.

I use this light (blinking) on my dog's collar and find it impossible for him to break by rolling on rocks....but the push button switch only lasts so long. I can usually get 40-50 hours out of it--then a battery change and another 40 hours but it is the switch that becomes harder, less consistent and finally gives out. I have to paint the edges with marine tape to tolerate the dog's occasional swim in the salt-water Bay. Still it shows up at a distance and beats out the other lights on the market for this purpose.

Well lets face it, DOG'S like to get wet. If there is a stream or lake or any body of water the dogs want to get in. The problem with this is that you don't think about taking it off before they go for their swim. I have has mine fail because there was moisture in it and it did not want to stay on. It still works, so that is a plus, but I thought that this would be something that I could leave on the collar. I would not suggest it. This is great if you walk your dog at night and will not be by any water for them to soak this in. Take it off after the walk and keep it with the leash and you will be happy. Keep it on your keys when you are not walking the dog and have a little extra light close at hand.