Tula straw hat with leather strap never worn in excellent condition Made of 100% natural palm fiber, Tula hats are naturally water resistant in addition to sustainable and environmentally friendly. Their unique overlapping layers of braided and sewn palm fibers give Tula hats the highest solar protection (UPF – Ultraviolet Protection Factor) rating on the market of 50+. Rigorously tested by California Polytechnic State University, Tula was actually commended for their excellent solar protection by the University: “The brim area of these hats is excellent, in fact, we have never tested anything with 0% transmittance. Congratulations on this protection!”