RockBand Flex -Heavy One band for mobility, flexibility and strength Forget latex and rubber. RockBand Flex is your all-in-one rehabilitation, stretch and mobility solution. Available in three resistances, RockBand Flex unlocks a universe of movement improvement and is designed to be washable, portable and infinitely reusable. One band, thousands of uses Get more flexible, improve range of motion, rehabilitate injuries and improve your strength with the ultimate all-in-one band. Made from a proprietary cotton-nylon blend, with 6-inch loops spaced equally on each half of the band, Flex allows an athlete to use one tool to rehabilitate injuries, improve mobility and increase strength.