Yep. While the blade style is a bit different, I think the S5 is a SY version of the RMD. A 5" long 3/16" thick saber ground blade of 52100 steel just works for me. And the mudder handle beats the heck out of the small handles on the YK and DM, even if it isn't quite as nice as the RMD handle. My only compaint with the RMD is the weight. It's a heavy knife for its size.