Now you can train two dogs at once! The Elite Big Dog Add-A-Dog Collar will work with any Elite Training System. It programs in seconds and converts your 1-dog system into an easy-to-use 2 dog system. You can also use it as a replacement collar for your one-dog system. With a range of 1,000 yards, 15 levels of correction, and a rechargeable battery, you can train your large dog in style.