EK ThreeD Black / Gold Chain - Z Series 525 - 120 LinksEK Chain set out to produce a premium chain that was as beautiful as it is strong. An impressive outer plate shape that offers a curved form to reduce weight and increase appeal is connected together with inner plates and pins that feature lightening holes to further reduce mass. Half of a pound lighter than most any other current high performance chain The exclusive SX2 Ring leads to 30% reduction of friction (compared with our exsisting products).