This beanie is great as a standalone accessory, but also works well under helmets and hats when a bit of extra coverage is needed. The fabric on this product is the powerhouse. Breathable and lightweight, the merino wool and TENCEL™ work together to provide odor resistant coverage while managing moisture, meaning this is a great option for an activity where you might work up a bit of a sweat. The TENCEL™ Active Cellulosic fibers are derived from renewable wood sources and the fabric is 100% biodegradable, meaning it's a sustainable option for all of your outdoor adventures.