Club Catcher | Lost Golf Club Alert System - Never Lose Another Golf Club Club Catcher is a smart sensor system that works with your phone to keep track of your golf clubs and quickly alert you if you leave one behind. The club units contain multiple sensors to know whether your clubs are in or out of the bag, and bluetooth to tell the app each clubs status. The free mobile app (iOS and Android) monitors your clubs going in and out to detect when youve left one behind, and gives you an alarm on your phone and smartwatch (optional) before you go to the next hole. Simply screw in the lightweight sensors to your club grips, download the free app, and be on your way! Club Catcher never interferes with your swing, and does not distract from your game. It works in the background with no cell service required - works in any phone mode including airplane mode and do not disturb. Club Catcher gives you peace of mind while you play. Tip: Most people get the 4-pack for their putter and wedges. We recommend having at least 2 club units for optimal functionality. If you only have one club unit, you may use the app in Pocket Mode with your phone in your pocket.