Jeff got it right
We got ours new, but there is lots of good discarded or salvage hardware out there. The West Marine catalog has good descriptions and discussions of line vangs - in the Harken section, I think.We added snap shackles on ours so it doubles as a preventer (attached to the end of the boom, and the toerail) or as a lifting fall to get someone out of the water in rough seas.An advantage of the solid vang is that you can do away with the topping lift.DavidLady Lillie