These X-ring chains have their unique ”X” shape that holds D.I.D’s special “V” grease and keeps dirt out of the chain’s links. If you take proper care of your chain, you get minimal chain wear. This could make your chain last at least 10 times longer. D.I.D’s X-ring seals provide 50% less friction and 50-100% longer life than a regular O-ring chain. Made of special alloy steel with solid rollers and bushings with precise tolerances and high cylindrical accuracy. This creates a low-friction chain, which leads to a longer service life. The VX chain is a bit narrower than other models which makes it light and flexible.