The Help ‘Em Up Harness Walking Leash/Shoulder Straps come in two sizes: medium/large and extra-large to accompany dogs using the medium, large and extra-large Help ‘Em Up Harness. The Walking Leash is adjustable and is used for walking, but also doubles as a shoulder strap for extra leverage when lifting and/or walking with bigger dogs. The Walking Leash/Shoulder strap is recommended for dogs using the Medium, Large, or X- Large Help ‘Em Up Harness; choose the leash size based on the size of your harness: M/L for medium and large harnesses, and XL leash for the XL harness or if you like having the extra strap for a large harness. For small dogs, we recommend using the walking handle.