The black seat cover has an elastic edge to fit snuggly over the OEM driver seat, passenger seat and passenger backrest. It is made of polyester, is UV and water repellent and is colorfast grade 4. The compact size makes it perfect for traveling and includes a carrying case. Works with or without the side mount driver backrests. This black rain seat cover measures 21 inches x 12 inches x 12 inches. Fits the GL1800s. Single.