First, the additional back flap is a kit that attaches to the upper back flap of one of the Canihunt brand vests to adapt the vest to the dog's morphology. It allows for an extension of up to 6 cm compared to the original flap. General features: Fabric type: 100% polyethylene, a puncture-resistant material that provides extremely effective protection against punctures. Reinforced seams: The crossed seams are reinforced with high-strength thread. It extends the original back flap by up to 6 cm. Thermoregulating lining Outlast®: Regulates the dog's body temperature, keeping it from getting too hot or too cold. Neon yellow color: Makes the dog visible during hunting and signals it to others (hunters, cars, etc.). Outer fabric: Ultra-technical Cordura® 1100 Dtex fabric with ripstop structure, tear-resistant and extremely abrasion-resistant. Compatibility: This kit is compatible with all Canihunt brand vests. Available in 11 different sizes: 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, and 95.