eXerband Exercise Tubing includes synthetic rubber tubing available in 6 colour-coded resistance levels. Proper use of the eXerband Resistance Tubing 30m Rolls for resistive exercise provides both positive and negative force on the muscles, improving strength, range of motion and cooperation of muscle groups. Colour-coded progressive resistance gives at-a-glance documentation of progress from one level to the next. With eXerband resistive exercise tubing, measuring progress and achieving goals for fitness or therapy is easier than ever before. The thickness of the tubing determines different resistance levels. eXerband exercise tubing was designed with colour-coded levels increasing in difficulty from yellow to silver. This comprehensive system provides positive reinforcement and feedback for gauging results. eXerband resistive exercise tubing costs much less, plus they are portable and versatile with virtually unlimited uses.