Leather Basket Muzzle (Boston). BM4, Black. 10.75" circumference, 4" length. Best fits breeds like Pit-Bulls. Constructed of 100% genuine cowhide Available in Black and 9 popular sizes Light weight and provides ample ventilation Best fits breeds like Pit-Bulls To fit correctly, measure: length from dog's eyes to the tip of the nose; circumference from 1 inch below the eyes and around the snout