I bought these LED dog collars for my dogs and her friends. The light is bright but would not irritate my dog. It is fully charged fast by USB but I have not tried the solar charge as the sunlight is not strong in this season. It is good to walk with my dogs at night in the park which is dark. Among the four collars I bought, one did not work. I requested to replace or return the collar. The seller replied me the next day in a very professional manner. It is a reliable seller. I will place more orders as gifts for my friends' dogs.