Ceiling Adapter with 2" Swiveling Coupler... This 6 inch x 6 inch adapter plate has a 2 inch threadedupling for national tapered pipe. It is used innjunction with our 2 inch single-pipe adjustable-height suspension adapter (AST-2446/2) for drop distances of more than 3 feet 10 inch. Pipeupling is slotted for safely routing signal cable through pipe interior.