Athlos Fitness Adjustable High Speed Cable Jump Rope 4 METAL BALL BEARINGS - Comes with 4 high-grade metal ball bearings. Designed specifically to increase revolutions per minute, helping you master double-unders and set new PRs. Ideal rope for CrossFit, Boxing, Endurance Training, and general cardio. This rope is for those ready to master double, and even triple unders as well as for those just starting out. Great way to get some cardio at home or at your box. Custom fit for all sizes, fully adjustable 10ft high quality and kink free wire cable, with lightweight ergonomic handles. One size fits all. One Year Warranty