The Laser Holder is designed to attach to a raw shaft or a finished club. The longer screw is used to fasten it to the shaft. Finger tight is sufficient to securely hold it to the shaft. The laser fits into the 1/2" hole in the holder and its ON/OFF switch must be aligned with to the threaded hole. The shorter screw can then be lightly screwed into this hole to turn on the laser. Very light pressure is needed. If the laser does not turn on the red switch is probably not centered in the hole. The three batteries are installed with the plus end toward to the back of the laser. Be careful when installing the batteries. The very fine threads can be cross threaded very easily.