I've seen people think that lupo is equivalent to .67 of wf1. Many people think that lupo is as aggressive as GC68, and its shaving efficiency is higher than GC68, somewhere between GC68 and GC84. If the lupo is only .61, then the design of lupo is really good, or the design of wolfman is very good.If I'm not mistaken, the Lupo is supposed to mimic the Wolfman WR1 .61 gap head.