Making rigging dreams come true. Downhaul primary line assembly using the two Harken 29mm Fly™ Blocks - The ultimate block for Laser downhaul solutions with one-piece titanium outer race/sheave, stainless steel ball bearings and inner race, and composite fiber-reinforced sideplates. Select your rig type and how you want to terminate the free end (either at the top of the kicker, or at the bottom of the kicker). The length of the primary line for Standard MkII is approx. 82cm from loop end to the top of the upper block. The length of the primary line for Radial/Standard MkI/4.7 is approx. 70cm from loop end to the top of the upper block. Lengths are 10cm less for top of kicker attachment.