The StrechCordz Kick Trainer adds resistance to legs during kick sets. Assists ankle recovery from breaststroke kick and adds resistance to abdominal muscles during dolphin kicks. The StrechCordz Kick Trainer includes two nylon shoulder harnesses and two adjustable foot harnesses that connect to two 20in/50cm tubes. No removable components or replacement parts. Sold as a single unit. Choose from 5 resistance levels. Silver has 3 - 8 lbs if resistance.