A hanger bar assembly for supporting an outlet box between spaced apart support elements including a first channel member being longitudinally slidingly engagable with a second channel member forming a longitudinally adjustable support bar. The polyester hollow molded product has a polyester coating layer on the exterior surface and the coating layer can be removed with hot water or alkaline aqueous solution. A pressure element is in operative connection with the tube. Movable optics may permit the same camera to focus on either distant objects or on a close-up bar code.