What Our Gearhead(R) Experts Are Saying:"I wear this under my jersey year-round, swapping heavier layers on top depending on the season. It never itches, never holds onto odor, and keeps me from overheating on long climbs."Temperature swings on a long ride can turn a jersey choice into guesswork, and the Merino Lightweight Sleeveless Base Layer takes that variable out of the equation. Worn close to the skin under a flyweight jersey in summer or layered beneath a thermal jacket in winter, it regulates body heat and manages moisture through climbs, descents, and everything in between. Natural merino wool brings anti-bacterial, itch-free comfort to a mesh construction built for breathability, so the layer disappears against skin no matter how long the ride runs or how much the weather shifts along the way.