... place battery' s positive pole toward the head, then screw on. 2. On / Off: rotate tight toward ... our directly. 3. Repeat the step 1, screw the cover tight clockwise.Maintainance: Use qualified battery. ... or other contactor poorly connected. (Solutions:Inject lubricant, screw down the ring on the Head and Tail.) 3, ... tail cap switch. (Solutions:Inject lubricant, screw down the ring on the Head and Tail.)