Plastic. Prevents the pet from licking or chewing wounds or bandages. With touch fastener for quick and exact fitting. Hemmed edges make it comfortable to wear and protect furniture and walls from being damaged. Transparent. Sizing information shows neck circumference/collar length. Size: 7# Suitable for neck circumference 15-18cm, depth 8cm, (small size) suitable for toy VIPs, Yorkshire terriers and other mini dogs, kittens6# Suitable for neck circumference 18-22cm, depth 11cm, (small size) suitable for small dogs, small and medium-sized cats such as Beijing and Baxi Shi5# Suitable for neck circumference 23-27cm, depth 12.5cm, (small size) suitable for small dogs such as Beijing-Brazil Shih, small and medium-sized cats4# Suitable for neck circumference 26-33cm, depth 12.5cm, (medium size) suitable for dogs such as Schnauzer, Shelty, Cocker, etc.3# Suitable for neck circumference 33-36cm, depth 13cm, (medium and large size) suitable for standard VIPs, Schnauzer, Shelton, Cocker Spaniel and other dogs2+# Suitable for neck circumference 35-40cm, depth 18cm, (large size) suitable for small golden retriever and Labrador2# Suitable for neck circumference 38-43cm, depth 20cm, (large size) suitable for small golden retriever and Labrador1#, suitable for neck circumference 42-46cm, height 22cm (large size) Try the large dog breed Golden Retriever, Greater Alaska, etc.