When I fist received these, I was very happy with the quality and the functionality (USB charging is a must for me, as I charge the lights on my work PC).
During the summer months they work fine, and the battery life is merely OK - but what do you expect, they are quite small, and charging is easy on the work PC, or via an AC cable (with USB extension cable - A USB cable like a phone charging will not work, you need a port).
However, after one small rain shower on the way home from work, the housing leaked water in and irreparably damaged the rear light - it would not switch on independently, only working wehn plugged in to a USB socket. To top it off, 3 days later, I removed the front light from my handlebars and the very small thin screw that holds the strap onto the body snaped off, rendering the front light useless.
Neither of the issues I have had are covered under the warranty, and you also have to return it to Hong Kong (where they are made), so very unhelpful on the customer service.
In summary, Initially I was very impressed with the technology and the size, however, the build quality, lack of customer service and the inability to survive a rain shower has poisoned me against moon lights forever... Avoid and spend a little more money on some better quality lights if you need them for more that a one-off journey