When you want to work with 2 dogs at the same time you'll want to couple them together. The Coupler device is light weight and short enough to give you more control than other couplers on the market. It is light-weight enough to use with Head Halters, though we NEVER recommend actually coupling two dogs together via the head halters. Instead PLEASE ONLY USE THE COUPLERS ON THE HARNESS!. This will keep them safely together.