I actually designed the Dual Handle Leash back in 1990 because I wanted a way to grasp the leash when I needed to bring my dog in next to me. There was one type on the market had a handle that hung down from the snap end of leash. That style did not work for me because my dogs walked thru bush and over logs as we explored the mountains. I needed a flat handle that was sewn in place from a one piece of webbing for the total leash. It gave me the flexibility to fold in place the handle at any level on the leash to work with different sizes of dogs. I prefer to have the dog walk slightly out in front off to one side of me; far enough that I can see the dog’s head in my lower vision. For me that is crucial for control of your dog, (See How to Use Harness and How to Use Leash for very helpful information).
I have over the years made some improvements with the Leash design associated with matching width of webbing used to make harnesses. The four widths of webbing used to make the leash sizes from X-Small to Large. The second handle placement and length are very important in each size of webbing due to our height and arm length related to the size of our dogs. I felt the design with the second handle was in the correct length needed for the hand to slide up and down to find that comfortable arm length between you and your pet. I use the second handle as a tool for my ability to control my pet; that ability to slide my hand quickly down on the leash to bring my pet near to me when need for safety. I can tell you once you use this tool; You will Love It!!!