A top-mounted, high-sensitivity GPS/GLONASS receiver, the T5 Dog Device Tracking Collar from Garmin uses LED beacon lights activated from a Garmin Astro 320 or Alpha 100 handheld device. The lights work in lowlight conditions and at night, and are visible up to 100 yards away. The device is rugged, water-resistant to 10 meters, and tough enough to run wherever your dog runs up to 9 miles away. The T5 Dog Device includes a 1" blue collar strap, rechargeable lithium-ion battery, charging clip, AC adapter, vehicle power cable, and manual. Dimensions: 3.5"W x 1.75"H x 1.85"D. Weight: 9.3 oz. with collar. Battery type: rechargeable lithium-ion pack. Battery life: 20-40 hours.