Your adventurous boy may not be summiting Mt. Rainier just yet, but he still necessitys a real jacket to keep him warm. The Fast Trek isn't bulky, but it keeps your active boy warm with 100% polyester 250g micro fleece. If it's a snowy day on the mountain or a chilly day in the park, this technical-looking jacket is as nice and lightweight as it is stylish and zippy. The full-zip fleece has raglan sleeves for mobility, and a vertical zippered security chest pocket for storage.