Description of Ice Breaker Rock Zip - Women's This is another classic Icebreaker that will never let you down. Warm mid weight, super-soft merino with stand-up rib collar and thumb loops. The contrasting panels ensure you'll look cool, even when you're perfectly warm. Features: Set-in sleeve with stand-up rib collar. Arching shoulder and arm stripe. Thumb loops. 100% pure merino. Fit: Regular