Outer diameter: 41 mm. PICTURES FOR ILLUSTRATIONS ONLY. The stanchion is 100% identical to the original in length, quality, and workmanship. Same specification as the O. High quality, all within factory tolerances. Made in Europe, not a cheap Chinese copy. High-quality industrial hard chrome finish. STAFF COMES DIRECT FROM A FACTORY IN POLAND. DUE TO CHANGE THE CARRIER HAPPENS RARELY. PLEASE CONTACT FOR MORE INFO.