The submitted sample is a bicycle trailer weather cover. The cover is made of man-made textile fabric, primarily polyester, with a urethane coating. The cover also has windows made of clear plastic, and various zippers, plastic buckles, metal snaps and grommets, etc. The cover is intended to keep rocks, rain, and other debris from injuring a child riding in the trailer. The cover is imported as a replacement part separately from the bicycle trailers.
[1] Please importantly note that only the relevant portion of the related is displayed above. You may refer to the said customs ruling for the entire ruling explanation.
[1]. https://rulings.cbp.gov/ruling/N067743