The R1 Speed Rope was not only designed and tested to outperform any other jump rope available but also has the claim of fame of being the world's fastest speed rope. The R1 Speed Rope has an ergonomically-designed handle that eliminates friction. Outstanding durability and unmatched speed in competitive categories. Made in the USA. SPECS: Height adjustable cord with a vinyl coating and technically superior speed bearings to ensure fluid and precise movement at high speeds. Adjusting the Rage R1 Speed Rope: Remove black vinyl cap from coated speed cable. Unscrew silver collar. Cut coated speed cable to desired length using wire cutters. Make sure 2 dots on handle swivel are facing direction of silver collar. Install silver collar and tighten set screw. How to Size Your Rope: Hold rope handles upright while placing both feet side by side while standing on the middle of the rope. General rule for length is to have the end of the handles reach your arm pits. Adjust length of rope until handles reach this point. For advanced athletes or as your technique advances, you will have to shorten your rope.