We sell hard hat liners that feature 100% Cotton. These hard hat liners are Ultra Light-Weight Rib Knit, Fit Under Hats/Helmets, require No Tying, and are One Size Fits All. The Hard-Hat Liner can be worn under any helmet, hat or even on its own. The ultra lightweight cotton liner is absorbent, breathable and makes wearing a helmet more comfortable. The liner is easy to use and requires no tying. A patent pending design allows for the wearer to maintain a full range of visibility while effectively shielding the neck from harmful UVA/UVB rays. The Hard-Hat Liner is compatible with most helmet suspensions.