This is a bicycle carrier that attaches to a roof rack using clamps. - The type that secures the down tube to the carrier. - The front and rear tires are secured to the carrier with belts to prevent movement. - End caps: Plastic Purchased about 20 years ago and used a few times, then stored indoors. The plastic parts may have deteriorated, but I didn't notice any when I looked at and touched them. The straps that secure the tires also seem to be in good condition. Due to this condition, please consider it as a junk item.