The behaviour of each golf shot is determined by how each swing delivers the clubhead to the ball. However, everything is moving much too fast for the golfer to see what is happening on impact. The author has presented the mathematical formula between major parameters of impact and the trajectory. However, no one would like to carry a computer with you to get information of your shots at the golf course. A simple device, called "VECTORS" based on the above-mentioned formula, enables you to identify easily what is happening at impact from the flight of your shots. The obtained information on the impact, such as the alignment of the clubface and the path of the swing, can be used to correct your swing on the spot. Once you have acquired the 3-D image of the device, you do not carry the device with you on the course or driving ranges.