Knog really sucks. The NERD is ok I gues, no problems yet, but the 4 Led rear light and the 1 led front light I use just suck. Keep losing contact and stop working, or battery drains. One of the two. So no matter what I do, they never work (except for the first week maybe). That was my second and last knog purchase. I expect the NERD to stop working in about a week or so. I'll report back if I am wrong.