MediCordz Single Modular Tubing - 4 Lengths & 10 Resistance Levels, Exercise Tubing, Rehab Tubing MediCordz Single Modular Tubing is used for individual exercise and stretching programs Also used for Rehab resistance programs and training Each MediCordz Tube includes fittings and plastic clips on each end for attachment. Consists of a single section of tubing, fittings and plastic clips on each end for attachment to modular components (blue and black resistance contains metal attachment clips) Tubing stretches up to 3 times its original length