Sorry for the inconvenience. We will definitely have it resolved as fast as possible.
Can you follow the steps below and check the light?
1. Test the light with a new set of AA batteries to rule out the battery problem if you have not done so.
2. Remove the pocket clip if it is installed on the light. It could prevent the tail cap from screwing down if being put in the wrong spot. (Please check the attached image for an illustration)
3. The flashlight can be unscrewed into three parts, a head, a body tube and a tail cap. When you put back all three parts, make sure the body tube is assembled in the correct direction. One end of the tube has an anodized thread (black thread). This has to be connected to the tail cap. The other end of the tube has an unanodized thread (shinny white thread). This has to be connected to the head. The light won't work if the tube is reversed.
