"The Garmin Alpha 300i Handheld Unit allows you to track and train your dogs when paired with compatible dog collars (not included). Featuring inReach satellite technology, this Garmin unit allows 2-way messaging and interactive SOS alerts (subscription required). Monitor up to 20 dogs from up to 9 miles away, and see it all on a vivid 3.5"" touchscreen display with up to a 2.5-second update rate. Easily control training functions by using the button-operated design. This Garmin Alpha offers 18 levels of stimulation when paired with your training-enabled collar. Premium Garmin navigation features include preloaded TopoActive maps, satellite imagery, multi-GNSS support, and a built-in 3-axis compass and barometric altimeter. This Garmin dog tracking device boasts up to 55 hours of battery life. inReach satellite technology for 2-way messaging and SOS alerts Monitors up to 20 dogs from up to 9 miles away Easy-to-read 3.5"" touchscreen with a 2.5-second update rate Button operation allows easy navigation 18 levels of stimulation when paired with a compatible collar Multi-GNSS support for accuracy Preloaded TopoActive maps Satellite imagery 3-axis compass Barometric altimeter"