Product Title:Dog Muzzle Silicone Duck Muzzle Mask for Pet Dogs Anti Bite Stop Barking Small Large Dog Mouth Muzzles Pet Dog Accessories. Size details: S: Mouth Circumference: 12cm/4.7 Neck Circumference (adjustable): 13cm - 27cm/4.7 - 10.6 Mouth Height: 4.5cm/1.7 (Approx.). M: Mouth Circumference: 15cm/6.10 Neck Circumference (adjustable): 13cm - 33cm/5.1 - 12.9 Mouth Height: 6cm/2.3 (Approx.). L: Mouth Circumference: 16cm/6.2 Neck Circumference (adjustable): 17cm - 35cm/6.6 - 13.7 Mouth Height: 7.5cm/2.9 (Approx.). Due to different measurement methods, please allow a measurement error of 2-3cm. Due to the problem of shooting tools and light, please allow the color difference between the picture and the product.