Hi Joanna! I could be mistaken, but I believe The Step Company is having their own tubing manufactured and packaged in with their step products. I would guess their purple tubing to be light-but-closer-to-medium in resistance. To give you an idea, I was using the yellow (light resistance) tubing by Power Systems before the purple tubing from the Step Company arrived. Once I switched to the purple tubing, the same exact exercises were tougher with the purple tubing. I hope this helps!