Castelli used state-of-the-art seamless knitting technology to make the Castelli
Iride Seamless Long Sleeve Base Layer for men their softest and most comfortable
base layer yet. Texturized polypropylene fibers next to the skin feel amazingly
soft and mechanically transport moisture to nylon outer fibers where it quickly
evaporates. As a final touch, Castelli added ultrasoft thumb loops to hold the
sleeves in place, covering the gap between your jacket and glove.