The comet long sleeve half zip impulse features icebreaker39s 150gm corespun fabric merino wool fibres wrapped around a nylon core for added strength and durability which retains next to skin softness in the underarm panels they use 120gm eyelet merino mesh fabric to aid in ventilation during high output days bonded seams eliminate chafing while thumbhole cuffs add a touch of warmth and functionality and make for easy layering the 39impulse39 print is organically inspired by the