KeepFresh Sand Bags Empty White Woven Polypropylene Bags w/ Ties - Pack of 20 Pack of 20 each - 14"x26" White Woven Polypropylene Sand Bags Woven polypropylene resists punctures and tears Built-in dark grey ties Maximum UVI protection - lasts 1,600 hours in the sun Dense, tight weave holds almost any dry substance