Size M (Cir: 8.75-9.5, length: 2.25-3) Size L (Cir: 9.75-11, length: 2.5-3.25). This dog muzzle is suitable for medium-sized dogs such as Border Collie, Beagle, Corgi, etc., but not recommended for aggressive dogs, highly anxious dogs, or flat-faced breeds like Bulldogs. Measure your dog's snout circumference and length according to the size chart or instructional video. Ensure the muzzle fits comfortably, with the nose not touching the front edge. Patiently train your dog to reduce resistance and escape attempts. As a training aid, it is normal for dogs to initially resist or remove the mesh muzzle. Gradual adjustment can be achieved through consistent positive reinforcement such as treats and praise. To reduce odor, air out the muzzle in a cool, well-ventilated area for a few days after opening. Alternatively, wash with mild detergent and air dry. The muzzle is non-toxic and safe for your dog's health. Help correct unwanted behaviors with muzzle training. Featuring a semi-enclosed design, this dog muzzle helps prevent biting, picking up objects, eating debris, and chewing inappropriate items. Note that the muzzle is a restraint tool and will not eliminate bad habits on its own. Behavior modification requires patience, consistent training, and proper guidance. Designed for maximum ventilation and comfort, this soft dog muzzle includes a breathable mesh and open-front structure that allows panting and helps regulate body temperature. Reduces the risk of overheating and nose irritation during walks, training, or play. Easy to put on and take off with an adjustable neck strap and quick-release buckle. Fits securely in seconds, making it convenient for daily use and ensuring a stress-free experience for both dog and owner. Offers a customizable fit with an adjustable strap at the top of the nose. Allows precise fitting to accommodate various snout shapes, ensuring a secure, comfortable, and snug fit.