Heavy duty highly polished stamped stainless steel. Supplied with black rubber mounting pads. Adjustable tube positions. Fits standard fiberglass 1-1/8" (2.86cm) I.D. base, 15' (457.2cm) outrigger poles. Base dimensions: 4" x 2-9/16" (10.16cm x 6.51cm). Fasten with #10 screws.