Retro Puff The Retro Puff Vest has a slim profile and a forgiving fit. Due to the combination of the stretch side panels and a flat-knit rib bottom, the Retro Puff Vest is one of the most comfortable vests Sun Mountain has offered. FEATURES Sustainable 37.5® insulation retains body heat, while 37.5 active particles embedded in the insulation accelerate vapor movement and prevent overheating and moisture build-up. 37.5 insulation provides an extreme weight-to-warmth ratio and never washes out or grows tired Zippered hand warmer pockets. Keep your game sharp with this reliable, comfortable, and stylish gear — made for modern golfers who want performance with personality.