The Walk'n'Train Head Halter display comes with 8 units, 2 each of 4 sizes (small, medium, large & x-large). This unique design fits like a collar, but works like a no-pull head halter by guiding the head - and where the head goes, the body follows. When you dog pulls, they receive gentle pressure on their snout to correct the unwanted behaviour. An included safety loop attaches to their regular collar so you still maintain control if they ship out of the head halter. "Coastal reserves the right to ship kits incomplete with no substitutions."