Constructed to provide buoyancy, along with a cozy secure fit, the Paws Aboard Pet Life Jackets features: An advanced breathable mesh underbelly for proper draining and drying, which provides your dog more comfort and healthier conditions than traditional pet life jackets, which can cause heat exhaustion and chafing. Features: New reflective strips for maximum visibility. Bright colors and unique designs. Handle on top for quick and easy grabbing. Adjustable nylon straps, Quick-release buckles. Heavy-duty yet more comfortable Velcro fastening system around the belly and neck to keep securely fastened. Extra Extra Small (1100): Weight: 0 - 6 lbs. Length: 6.5 inches. Neck Girth: 7 - 9 inches. Body Girth: 11 - 16 inches. Extra Small (1200): Weight: 7 - 15 lbs. Length: 8.5 inches. Neck Girth: 8 - 12 inches. Body Girth: 15 - 19 inches. Small (1300): Weight: 15 - 20 lbs. Length: 11 inches. Neck Girth: 12 - 20 inches. Body Girth: 17 - 22 inches. Medium (1400): Weight: 20 - 50 lbs. Length: 14 inches. Neck Girth: 20 - 25 inches. Body Girth: 21 - 30 inches. Large (1500): Weight: 50 - 90 lbs. Length: 16 inches. Neck Girth: 24 - 30 inches. Body Girth: 30 - 37 inches. Extra Large (1600): Weight: over 90 lbs. Length: 20 inches. Neck Girth: 29 - 34 inches. Body Girth: 36 - 44 inches.