ADJ CLNG EXT 7-9FT JUMBO MOUNT Peerless Adjustable Length Extension Columns allow the TV Mount or Projector Mount to be extended below the ceiling fixture. The tube-in-tube design is adjustable (prior to installation) at 1" (25.4 mm.) increments. A nut and bolt secures the column at the desired length. Both ends of the column assembly consist of schedule 40 tubing, 1 1/2-11.5 NPT threaded, and notched for safety locking.