this is a pony bitless that is hand braided in the USA. You can use it with the hackamore included or take the hackamore off and add a bit. It comes in two sizes...small pony and large pony. A small pony is your typical mini or sheltand pony. A large pony is your typical Welsh pony. The small pony or mini - lets out to 17" around the nose (where the halter noseband fits) and lets out to 30" from one side of the mouth behind the ears to the other side of the mouth. The large pony - lets out to 21" around the nose (where the halter noseband fits) and lets out to 39" from one side of the mouth behind the ears to the other side of the mouth