Light Up LED DOG Harness with Reflective Strip Adjustable Sizes: Small (width 0.78in chest 16in-18in), Medium (width 0.98in chest 20in-22in), Large (width 0.98in chest 23in-26in), Extra Large (width 0.98in chest 27in-32in) 3 Flash Modes: Solid, Blink Fast, Blink Slow Perfect for Walking, Running, Hiking and Camping. Keeps your dog visible and safe at night. Battery Life: 60 hrs run time continuously. Tip: For Longest Battery Life use "Blink Slow" mode. Water resistant and great for all conditions, light weight, durable. Easy to Replace Batteries and comfy around your dogs neck.