CHOD rigs are used in carp fishing and consist of a mainline, a leadcore leader, a hooklink and a hook. The mainline is typically made of braided line and is attached to the leadcore leader, which is made of a heavy duty fishing line with a lead core. The hooklink is typically made of monofilament or fluorocarbon fishing line and is attached to the hook. The rig is designed so that the leadcore leader sinks to the bottom and the hooklink floats above the bottom, making it easier for the fish to take the bait.