Yuppie Puppy Sporn Training Halter Medium Description Stops Pulling Instantly! The Original Sporn Halter® was invented by Joseph Sporn in 1992. The Sporn Halter® is made of the highest quality braided cord and nylon webbing with thermoplastic and nickel-plated steel fasteners for extra durability. Restraints™ are threaded through the padded Sherpa Sleeves™ to provide maximum comfort for your dog. Available in 4 sizes and is easily transformed to a standard collar when the anti-pull functionality is not needed. Sizing Recommendations Small: 9-12 inch neck and approximately 8-25 pounds Medium: 12-17 inch neck and approximately 25-60 pounds Large: 16-24 inch neck and approximately 60-90 pounds Extra Large: 23-33 inch neck and over 90 pounds Recommended for walking purposes only; not to be used as a tie-out or car harness. The nylon restraints and sherpa sleeves can detach from the Sporn collar so that only the standard collar can be used when the anti-pull function is not needed. We do not recommend leaving the entire Halter on a dog unattended.