Icebreaker Size Chart A lightweight technical zip-neck baselayer designed with Icebreaker's BodyfitZONE(TM) construction, the 150 Zone Long Sleeve Half Zip offers intelligent ventilation for year-round moisture management and stretchy, quick-drying performance. A versatile baselayer that works layered up on the ski hill as well as worn alone on a warm trail run, the Zone features Icebreaker's corespun fibers-nylon threads wrapped in soft merino wool and blended with LYCRA(R) for the ultimate combination of durability, stretch and next-to-skin softness. Strategically zoned panels of highly breathable merino mesh increase ventilation for high-output days, and the zip-neck design allows you to quickly dump excess heat. Underarm gussets and raglan sleeves improve range of motion, and flatlock stitching prevents chafing during dynamic pursuits. Features: - Corespun fabric for enhanced durability - LYCRA(R) content for stretch and mobility - Zip neck collar for temperature regulation - Strategically placed merino mesh for ventilation - Flatlock seams prevent chafing - Raglan sleeve construction for mobility - Underarm gusset for comfort and mobility - Dropped front and back hem for added coverage - Center back length: 72.7cm/38 1/2", size M - Icebreaker heat transfer logo - Fabric Weight: 150 Ultralight - Fabric: Body: 83% Merino Wool, 12% Nylon, 5% LYCRA(R) Eyelet: 85% Merino Wool, 14% Nylon, 1% LYCRA(R) - Product Weight: Medium = 168 g / 5.92 oz - Alternate images show different colorways, yet accurately display product features