Trixie Classic Dog Collar (M-L, 35-55 cm / 20 mm, Black) :- Trixie premium and Classic dog collars have a high-quality nylon strap. This collar for dogs is extra robust due to strain relief. It is durable and tear-proof. It is fully adjustable to your dog's neck. This collar is in basic dog training. It will be the right collar for your dog. Trixie Classic Dog Collar (S-M, Black) :- Trixie premium and Classic dog collars have a high-quality nylon strap. This collar for dogs is extra robust due to strain relief. It is durable and tear-proof. It is fully adjustable to your dog's neck. This collar is in basic dog training. It will be the right collar for your dog.