We built the Nano Puff® Vest for climbers who needed a weather-resistant, lightweight and packable synthetic insulation layer that could stay warm even when wet and withstand seasons of use. Ever since, those same features have made it the uncontested favorite midlayer for just about any outdoor pursuit. With fit refinements for improved mobility, 60-g PrimaLoft® Gold Insulation Eco 100% postconsumer recycled polyester with P.U.R.E.™ (Produced Using Reduced Emissions) technology, and a 100% recycled polyester shell and lining.