500 gsm virgin poly-propylene (PP) multifilament, 500 denier in warp PP, hollow tube in weft. fire retardant* to pass CPAI 84/5. Made in tightly woven twill structure, double thickness (2/1, 3/1, 2/2, 3/2), with minimum 1,000 tubes/meter length. With heavy-duty ribbon, strongly stitched around the entire perimeter.