Features - Color: Blue - Material: Dacron and plastic - Size: About Chest bust:XS size 30-35cm width 1.5cm [4 cr2016 button batteries] Chest bust :S size 32-37cm width 2.0cm [4 cr2032 button batteries] Chest bust :M size 38-46cm width: 2.5cm [4 cr2032 button batteries] Chest bust :L size 46-55cm width 2.5cm [4 cr2032 button batteries] Chest bust :XL size 62-68cm width 2.5cm [4 cr2032 button batteries] Light mode: long light - flash - slow flash Optical fiber style luminous principle: LED lamp luminous - through optical fiber light Continuous long light lasts for about 40 hours, Shine for up to 50 hours and the battery is replaceable - Adjustable harness and hauling cable allow you to create a comfortable feeling for your pet. - Harness is breathable, keeps your dog cool - Suitable for the most dogs and pets. - Warm Tip: Dear buyer, due to lighting effect, monitor's brightness, manual measurement, etc., there could be some slight differences in the color and size between the photo and the actual item. Sincerely hope that you can understand