Brandon, No worries. Reynolds is a brand that makes tubing for lots of applications, aerospace, bikes...all kinds of stuff. Super high end. 853 is one of the levels of Steel tubing that they do. Basically, they are butted tubes. So the walls are thicker at the ends where the stress and welds are, rather than straight gauge (Straight = thick and heavy) Chromoly tubing that most of the aforementioned bikes use. This link shows the increased strength to weight ratios for Reynolds tubesets. http://www.reynoldstechnology.biz/downloads/materialcompweb.pdf Thanks for asking, as I promise you're not the only one who didn't know. ;0)