Extra Heavy Blue Tubes are the fifth of eight levels of resistance and great for rehabilitation and moderate to high resistance exercise, they offer 5.8 lbs. resistance and 25% increase from preceding color at 100% elongation and 8.6 lbs. at 200% To be used in conjunction with THERABAND Rehab and Wellness, Exercise and Wall Stations Tubing designed for use with the Exercise Station and Wall Station is available in 4 color-coded levels of resistance (Yellow, Red, Green & Blue) and 3 different lengths (12", 18" & 24") Comes with clip connectors Easy to use, set of 2