Compatible with the following Garmin golf watches S70 S50 S44 Get the most from every game you play with tour player stats available and your average club distance on your compatible Garmin watch when you pull out your club, they combine with the Garmin golf app to offer a real insight into your game. The sensors simply twist into the hole at the top of your grip and then are easily paired with your compatible smartphone through the Garmin app. As you hit a shot with a club with a paired sensor it will register the distance you hit based on the position of your next shot and over time collect stats for that club. Each time you pull a club out of the bag your compatible watch will show the distance you typically hit that club - real information learnt on the course in true playing conditions. Attach one to your putter and the app will know when you take a putt for review later on through Garmin connect. Review your round later on the Garmin app and see the stats for your round. Each hole can be viewed showing exactly where you played from, what club you used and how far it went. Historic shots of yours on that same hole can also be viewed if you wish (yellow dots on picture below) Battery free technology so never worry about recharging or changing batteries. This is a full 16 piece set for every club in your bag.