2 comps; unit = unit. They are virtually same insulins made by 2 different companies and they do pretty much exactly the same thing, unit for unit. Novolin n/r or combo of two as 70/30 (70%n, 30%r--r =regular, fast acting, n=normal, longer acting). Humalin n/r or combo 70/30...So for all practical purposes, these two insulins are interchangeable. Consult doc if have concerns. Good luck.