The Moonstar collar is the "Dog Star" collar of the constellation - the brightest star in the sky! Soft, breathable nylon design makes our walking sets super comfortable, stylish, chic and fun to wear. Sizes: small, medium or large (select your size + refer to sizing reference) Ultra-strong nylon webbing Soft, Breathable, comfortable fit 2-Sided printed pattern Durable alloy natural-brass hardware Sturdy, alloy metal D-ring for leash attachment Double-stitched for durability + strength Hand wash + Air dry How to Select the Best Collar Size: Loosely measure your dog's neck with a soft tape measure where the collar would normally sit. Slide in two fingers between the dog's neck and the measuring tape. This fitting will give your dog a comfortable collar size. Another option is to measure your dog's neck, then add 2 inches for the best fit.