This Spreader Flag Halyard Kit is everything you need to rig a flag halyard to your spreader: 40 ft of 3/16" polyester line, a block with a pad eye for mounting on the underside of the spreader, a shroud cleat with wire rope clamp, and (2) bronze snaps.
This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm.
www.P65Warnings.ca.gov