VIZPET Light up Dog Collar Super Bright Keep Your Dog Safety in Dark Night. Vizpet Nylon led Dog Collar with high quality flat optical fibers makes your dog for great identification and safety around the 500 meters. No more worries about the dog safety. Our light up dog collar is waterproof , you don't worry about rainy days, snowy days. But can not be immersed in water for a long time, such as swimming.Our usb rechargeable led dog collar with 140 mah battery, fulled charged 2hs. Note: Please use 5V adapter only.A metal D-ring is so nice and does not rust. You can use it with a dog leash. Vizpet Gowing Dog Collar is a great way to keep your dog safe.5 color : Green, Blue, Orange, Red，Pink .You can choose the color according to your favorite and pet personality.3 Mode Lights：Fash Glowing-Slow Glowing- Steady Glowing. When the collar is fully charged, it can be used for 6- 8 hours fast flashing, 10-12 hours for slow flashing, and 4-6 hours of steady glow . Each mode has applicable scenarios, which can make your pets safer at night and give you more peace of mind. Package include: 1 X VIZPET Dog Collar, 1X USB Cable There are total 4 sizes: Small, Medium, Large, X-Large Please simply measure your dog's neck and choose the appropriate size. Small: 11.02-15.74 inch（28-40cm）Medium: 14.96-19.68 inch（38-50cm） Large: 18.89-23.62 inch（48-60cm） X-Large: 22.83-27.62 inch（58-70cm） Each size has an adjustable range，you can adjust the size with a release buckle according to your dog's neck size. Note:For manual measurement, there maybe an error of 1-2cm, subject to the actual product.