Spin Brightz LED Bicycle Spoke Tube Lights, Weather-Resistant, for 1 Wheel, Blue

This is a really cool bike accessory that is also great for safety. I love love love that you can replace the battery. I put it on my child-carrying bike trailer to haul my kids around for trick or treating. It takes a little effort to snap the lights on, but they definitely aren't going to be falling off unless you drop your bike really hard and hit them roughly enough to break them. I didn't experience any tangling of the wires. The lights have three patterns: fast blink, slow blink, and solid. They are very bright. I think it would be a great design idea to make the lights where they can disconnect from the wire without disrupting the flow of electricity so in case one breaks you don't have to remove all of them from your bike. 

My daughter just learned to ride her bike a few months ago, she is tall so the bike she is using it will be small for her soon, we got a new bigger bike for her and we added these cool lights, they match perfectly with the bike colors, this bike with the lights will be her Christmas present, the lights have 3 modes, blinking, slower blinking and on all the time, easy to install and take out as needed, she will love it.