Comfortable Soft mesh fabric Lightweight and breathable Adjustable chest strap Includes metal D-ring for leash attachment Size Large fits the dog's 14" neck, chest size 19-29" Size Small fits the dog's 9.8" neck, chest size 12-18" Note: Using a measuring tape, measure the length around your dog's neck and your dog's chest at its widest point which is usually behind the front legs. As you know, the different computers display colors differently, the color of the actual item may vary slightly from the following images.