If you want to practice & analyse your golf swing then this product is just for you. At one third of an ounce, it is the lightest portable golf swing analyser, which uses advance motion sensor technology to collect swing data & display the analysed results on your mobile smart devices 3 Bays GSA™ provides swing arc animation & 10 valuable swing parameters complied from 10, 000 data points captured from your swing for immediate review on your smart phones & tablets via the free GSA app.