What Our Gearhead(R) Experts Are Saying:"I keep this in my pocket all winter. It's ultra-thin, slides under any helmet, and the Thermax fabric actually wicks instead of getting clammy. I swap between balaclava and neck gaiter on the fly, and the 4-way stretch keeps it put during storm laps and cold runs."When temps drop but we're still moving, we reach for the Seirus Thermax Headliner Balaclava. This ultra-thin, low-bulk layer adds just enough warmth and wind protection while breathing and wicking to keep us comfortable from lift rides to frosty trail runs. Versatile by design, the Thermax Headliner works as a helmet liner, full balaclava, skull cap, or neck-up. Four-way stretch creates a smooth, stay-put fit under helmets and hoods, and the quick-drying fabric helps seal out the chill without overheating when we push the pace.