LET'S MEASURE & BUY THE CORRECT SIZE: Neck: Measure around your dog's neck leaving room for two fingers. Chest: Most important measurement; measure your dog's chest around the widest part. Add 2 inches for comfort. If your pet falls somewhere between two sizes, we advise ordering the larger of the two. GIVE YOUR DOGS A WARM WINTER: Waterproof surface with soft warm fleece padded and thick cotton inner, keep your pets warm in the winter. Even in the heavy snow, in the cold wind, still make your dogs feel warm and comfortable. Light weight suit for daily wearing. PROTECT YOUR DOGS SAFE IN THE DARK: Large area of reflective elements will be very conspicuous in the dark, Keep your dog safe at night. EASY ON: Design of abdominal button easy to put on & take off. The bottom button can be adjusted to fit your dog better. The design of the abdomen will not affect your dog's pee. Machine washable. D RING ON BACK: There is a D ring on the back with strong stitches easy to walk the dogs, But if its a long-term strenuous exercise, we suggest you choose other Didog dogs harness or collar.