Stroops Slastix 4-Foot Very Heavy Toner, Green Slastix products evolve way athletes train with resistance tubing, improving upon traditional "naked" tubing for increased safety and comfort Gathered fabric exterior protects core tubing from wear, nicks, and cuts; tubes can stretch up to three times their length Working out with Slastix bands helps develop long, lean musculature Bands come in various strengths to accommodate different strength levels Four-foot green band is rated at very heavy resistance (33 pounds)