K710 Kool Chain
For the "Kool" guys KMC makes this chain with an impressive tensile strength of 1,300 Kg.
It fits most sprockets/freewheels/cogs and is smooth on the outside so it doesn't get stuck on
a handrail or coping. It is also available in the K710SL (Super Light) version, which is nearly 20%
lighter than the K710!

K910 Kool Chain
The K910 is a bigger version of the K710 Kool chain with a tensile strength of a whopping 1,500 Kg.
BMX Freestyle has lots of street riders who cannot use a normal chain, simply because the chains are
not strong enough for their type of riding. KMC makes this Fat Kool Chain for those whose main
concern is chain strength rather than weight.

Z510HX & Z610HX
This is a perfect chain for racing and Heavy Duty BMX use, the tensile strength is a good 1,200 Kg. It
can be used on almost every front sprocket and rear freewheel/Cog. Light but strong, this chain is a
bestseller in the BMX Freestyle world, but it is also becoming very popular in the mid-high end range
internal gear hub equipped bikes, because of it's long life and high reliability.



Source: http://www.kmcchain.com/index.php?ln=en&fn=bu_bicycle#a