Question for Swingback owners

[Renegade34]

Hi all, I was wondering if someone who owns a swingback (with rail keeper) could kindly give me a diameter of the rail and also the support bar of the ski tow bar. I don't have the boat yet but would like to order a couple of rod holders that attach to the railing (or support bar). I'd greatly appreciate it if someone could provide that info. Thanks in advance!