The butyl bladders currently used in Fuluma balls have a 50% butyl and 50% rubber content. This composition differs from some cheaper versions available on the market with a lower often 30% butyl content. Butyl bladders have a much higher air retention capacity. The more butyl, the better the performance of the bladders. Due to the specially designed butyl valve, a soccer ball with a butyl bladder will hold its air for a particularly long time.