Slimline turnbuckles provide tension to the cable run.  Use on runs of no more than twenty feet in length.  Mounted to ceiling or wall.  When ceiling mounted, cables drop 1 inch from the ceiling.  Use the 1.5 inch washer (included) for ceiling mount support on runs over ten feet.  Order isolating slimline turnbuckles when mounting to a metal surface or metal studs.  Finish is Sayin Nickel.  Sold as pair.  ETL listed.