The New Garmin T5 add – A – Dog GPS Dog Tracking Collarallows you to add an extra dog collar to the Garmin ALPHA Dog Tracking system. This collar allows you to track a dog up to 7 km’s range. The Garmin ALPHA Dog Trackeris expandable to track up to 20 dogs (T5 Collars). This collar is fully waterproof and rechargeable with 4 hours fast charge as well as user easy replaceable battery.