" Sunlight-Readable 26 color displaybr Expanded Internal Memory 8GBbr DUAL BATTERY SYSTEM Use with 2 traditional AA batteries or the optional rechargeable NiMH battery pack that can be charged while inside the devicebr Receive Smart Notifications and pair with optional ANT sensors such as heart rate monitor Tempe temperature sensor speedcadence or use to control your VIRB action camera 64s64st onlybr Wirelessly upload data to Garmin Connect and view on smartphone plus share activities as they happen with Live Track 64s64st only br Garmin GPSMAP 64st TOPO U.S.