The Herm Sprenger Prong Dog Training Collar is an anti-pull training collar that is made of high-quality materials. It is designed to help keep your dog safe and secure. The collar features a center plate that positions the links to apply even pressure to the dogs neck. The collar also has a swivel ring for leash attachment. The small size (2.25 mm x 16 inches) fits dogs with a neck size up to 13 inches.