Soft but very strong fabric, Allows the dog to breath and pant normally limiting unnecessary stress. Size Guide 0 - Tiny Dogs (Yorkies) - (Noseband 10cm) 1 - Whippets - (Noseband 12cm) 2 - Border Collies - (Noseband 14cm) 3 - Labradors - (Noseband 18.5cm) 4 - Rottweilers - (Noseband 21.5cm) 4XL - Extra Large Rottweilers - (Noseband 26.5cm) 5 - Great Danes - (Noseband 24cm) 5XL - Extra Large Great Dane - (Noseband 28.5cm)