* The patented Xertube will help you build explosive power in your punches, and increased speed of your defenses
* The Xertube offers progressive resistance levels for multiple uses and fitness levels
* Allows for isolation of targeted muscle groups and full range of motion exercise
* Ideal for group exercise, personal training, and traveling
* Yellow is the easiest resistance and purple is the most challenging
* Each color is sold separately
* Resistance by color:
Yellow - Very light
Green - Light
Red - Medium
Blue - Heavy
Purple - Ultra Heavy