Actually bought these rear bike lights primarily for running at night. Brightness, durability and compactness surpassed by none.
This is my second plus rear light since the button on my last one tore off, but truly that was my own fault for keeping it in my Ortlieb bag with my heavy bike tools. Otherwise, I love the simplicity of how this light charges, how portable and bright it is, and the price. Remember to hold the button down to power on the light. The packaging doesn't say to hold the button down to power it on, but the online user manual does.
Awesome rear light with many modes more or less energy saving depending on the brightness. Very slim, looks perfect for those narrow aero seat posts, even though the longest elastic band is "limit short" for a Canyon Aeroad seat post.
This light is bright and versatile. I attach to the frame using the strong bands and it also slides nicely on to strapping on my pack pack.