1.) Use a tape measure to measure your dog's neck where it is placed. Be sure to leave enough breathing room 2 fingers wide. 2. Hybrid Collars and Hardware - Built for all breeds, this hybrid collar intentionally maintains a lightweight design, built with heavy hardware. Our newly designed metal/plastic hybrid buckles reduce the clang of traditional metal buckles while making them more comfortable in everyday use. 3. Neoprene mat - give your dog the comfort he/she deserves. Each collar is lined with soft neoprene padding to protect the dog's neck from irritation during movement. Don't worry about smells or your dog playing in the water. Our neoprene dries easily and is odour-resistant. 4. Reflection - Visibility is essential for early morning and evening walks. This collar has a reflective light that runs down the center of the collar and helps ensure your dog is easily visible in poor lighting.