Review on SIGEM Bike Light Set: Ultra Bright, USB Rechargeable LED Front Headlight, Rear Taillight, and Helmet Light for Easy Installation. Waterproof Bicycle Head & Tail Lights (3 Pack). by Mike Dart

Pretty basic light. That's what you should expect, starting at $20 for a set. It's a little annoying having to keep pressing the button to see all the toggle options. Nicer lights, you can press and hold the button for a second or two and it will turn off, this one doesn't. Another feature of nicer flashlights is the ability to LOCK them. So if you leave them in your backpack or whatever for a while, you can LOCK them and they won't accidentally turn on. .What I can have though is that the light turns on by itself when installed on the bike (not in the backpack otherwise the button could be pressed) and during the day. By the time I needed the light it had completely drained the battery. Maybe because of the rain that day? But they must be waterproof! When I noticed the light was on and tried to turn it off, it didn't respond to button presses. So I would say spend your money on a better light that you can really count on. And now the taillight button doesn't work at all. DO NOT BUY THESE USELESS LIGHTS!