The Sonic Ultra Zip is a highly efficient mountain running layer. Slim fitting, adaptable and built with unhindered articulation and an odour control finish. Designed to offer you a layer of protection on cooler days when a tee wont cut it, or hotter days when covering up from the sun is key, its responsive to your output, eliminating the need to constantly change layers. Highly responsive to your output, the Sonic Ultra Zip is cleverly designed to regulate your temperature. Built with ultralight Motiv Aero fabric, it is fast-drying, quick-wicking and highly breathable. With its subtle mesh structure, the fabric wicks moisture away from the skin keeping you dry on those steep, challenging climbs. It has laser cut vent holes in high heat areas, like the back of the neck and under the arms, and the deep chest zip is ideal for dumping heat quickly and keep the air flowing. Perfect for runners travelling far and fast, crossing contours, and weathering all conditions.