360º Swivel-Mount Clamp, for "2.5-inch" pipe diameter (actual dia.: 2.5 in.) Actual clamp inner diameter is 2.5 in. (63.5 mm). Highly-polished, machined, corrosion-resistant 6463 aluminum alloy. Center bore allows speaker wire to be run through the mounting spline for invisible wire routing, also permitting rotation of the enclosure after wiring. Only for use with JL Audio Enclosed Tower Speaker Systems, model M770-ETX-CG-WH and M770-ETX-SG-TB. Sold individually.