Keep your canine companion found with the Garmin Astro GPS-based dog tracking system, and leave the bushwhacking to your dog Bundle includes full-featured Astro 220 GPS unit and the DC 30 dog-collar transmitter for relaying dogs position to you every 5, 10 or 30 seconds. Intuitive setup can be readied for tracking in minutes, keeping user apprised of up to 10 dogs positions additional DC 30 transmitters not included. DC 30 transmitter collar is weighted to maintain position of transmitter above dogs back. Flexible antenna on DC 30 withstands rugged use in brush. Up to 7 mi. line-of-sight range, depending on terrain. DC 30 transmitter offers 17 to 36 hours based on position pinpointing frequency on rechargeable lithium ion battery pack includes AC wall adapter and DC vehicle charger. Astro 220 GPS offers full mapping abilities with optional map software and is compatible with data cards via the microSD card slot. Features barometric altimeter sensor and electronic compass for accurately tracking pressure changes, altitude and direction. Scratch-resistant lens protects sunlight-readable 2.6 in. color TFT display with backlight and rocker keypad navigation. Arrive easily at your destination with automatic routing and turn-by-turn directions. Flexible antenna tracks up to 10 DC 30 transmitters dog tracker page indicates dogs position relative to the Astro 220. Dog map page shows not only where each dog is every 5, 10 or 30 seconds but also shows a route of the ground covered by each dog. Dog page can also indicate whether your dog is running, sitting, on point, or treeing quarry from sensor information inside DC 30 transmitter. Covey Counter waypoints store additional data about the covey including how many birds were flushed and how many were taken. Hunt and fish time page displays good and best time ranges for your current location.