Arccos Caddie Link Arccos Caddie sensors (sold separately) are required Wearable shot-tracking device (can be clipped at waist bend, belt or pocket) Wirelessly connects with your phone and syncs to smart sensors in your club to track your shots Allows you to mark hole locations with a push of a button when standing next to pin Small and lightweight Weather-resistant Battery life of up to 10 hours Quickly charges via standard micro USB cable