3Bays iOS Version Golf Putter Analyzer At one third of an ounce, 3BaysGSA Putt is the world's lightest putt swing analyzer, which fits perfectly to the end of golf club Uses advanced sensors to digitize putt motion and deliver putt plane playback along with key putt metrics to smartphone/tablet on GSA Putt app Golfers can compare putt with their best ones or instructors' to make adjustments, thus pursue more powerful, accurate and consistent putts Comes with leather carrying case, USB charger & Quick Start Guide