Jardin Night Reflective Pet Dog Saver Life Jacket, Small Size: small; the pet saver vest is ultimate buoyant floatation device designed to keep dogsin and around water, while allowing for maximum comfort Exceptionally durable materials that meet rigidspecifications provide warmth and protection from abrasions Neon orange night reflective stripes on the back. Size: Small ( Fits 8"-12" Base of Neck to Base of Tail. Fits 10"-12" Necks. Fits 18"-24" Chests. ) Measure length of pet's back from the base of neck to the base of the tail If measurement is between sizes, we recommend up one size if pet has a stout build, deep chest, or overweight, we recommend up a minimum of one size