Material: Aluminum-Magnesium Alloy 535Finish: MillRound Base Size: 3-1/2"I.D. Size: 1-5/8"Pipe Size: 1-1/4"Set Screw Size: 3/8"-16 Thread X 1/2" LengthHex Key Size: 3/16"Mounting Hole Size: 9/16"Elongated Mounting Hole Is Inside Of Fitting For Clean LookCan Be Used With Any Pipe Including Aluminum, Galvanized Steel, Stainless Steel And Black IronHigh Corrosion Resistance