Armycrew Thin Blue Line American Flag 3D Rubber Tactical Patch Air Mesh Flex Cap. 50% Polyester , 50% Cotton. Extremely Durable Molded Thin Blue Line American Flag 3-D Rubber Patch. Patch Has a Rear Hook Backing For Easy Adjustments. 2 structured front panels with 4 air mesh back panels, stiff and pre-curved bill. Featured with an inner elastic sweatband, Finished with a stretchable fitted end/closure. 2 sizes available; S/M and L/XL.