Alpha 10 works with compatible Garmin dog collars to monitor up to 20 dogs from up to 9 miles (depending on the dog collar) with a 2.5-second update rate; Access multiple global navigation satellite systems (GPS and Galileo) to track in more challenging environments than GPS alone; With up to a full week's worth of battery life (40 hours of use), you'll stay charged and ready for action, even on multiday trips; Momentary and continuous stimulation options let you customize training for each dog (when paired with select dog collars; sold separately); Issue different levels of audible tone or vibration commands for quick adjustments to individual dogs (when paired with select dog collars; sold separately); Pair with the Garmin Explore app on your compatible smartphone to see real-time dog tracking information, save collections of dog tracks and replay tracks to see exactly what happened during your hunt; Track fellow hunters by pairing Alpha 10 with other compatible Alpha and Astro handheld devices