| RefrigiWear Skinny Cap | Multicolor | Ragg Wool/Acrylic. RefrigiWear Just because it's skinny doesn't mean it isn't strong. The Skinny Cap is thin enough to to fit under other headwear, including hard hats, but it still keeps you warm on the cold days. Plus, it conforms to your head for a snug and comfortable fit. Soft acrylic knit Skinny knit conforms to head Fits under hard hats Embroidery available RefrigiWear Skinny Cap | Multicolor | Ragg Wool/Acrylic... - RefrigiWear Skinny Cap | Multicolor | Ragg Wool/Acrylic. |