MEDIUM - Fits dogs with a neck circumference between 14 inches to 19 inches. Fits most dogs that weigh between 30 lbs and 60 lbs. HI VIS BLAZE ORANGE FABRIC - The 300D Oxford weave blaze orange fabric keeps your dog visible to you and others maintaining your line of sight and helping to prevent automobile and hunting accidents on or off leash. SUPERIOR REFLECTIVITY - Donned with reflective piping and a reflective heart paw to increase visibility in low light situations. Reflection from a light source, such as flashlight, can be reflected back up to 500 feet of distance. (This not battery powered) ADJUSTABLE STRONG FASTENER - Ample length of hook and loop fastener allows for the perfect customized fit for your PUP. ksdfjoeiruoiejfe kdfjoiej