TheraBand Professional Latex Resistance Bands are available in 8 color-coded levels of Progressive Resistance. Proper use of these systems for resistive exercise provides both positive and negative force on the muscles, improving strength, range of motion and flexibility. Color-coded progressive resistance gives at-a-glance documentation of progress from one level to the next and allows the user to progress as they get stronger. The red bands are for medium resistance. TheraBand is highly portable and versatile with virtually unlimited uses.