The Mendota EZ-Trainer Lead/Leash was designed in cooperation with a leading dog trainer of obedience and field. Through a program of repeat training, this product makes training EZ. The Mendota EZ Trainer is easy to use, simply Snap to ring on your own collar, slide ring to middle of dog's chest or waist and run the end of the lead/leash around chest or waist and through ring (clockwise to heel on left and counterclockwise to heel on right). Heeling-Walk or run with lead through ring. Sitting-Place hand at the ring, a press down on rump. Jumping Up-Simply pull back on lead/leash. FITS ON ANY COLLAR - COLLARS SOLD SEPERATELY