Where's The Fish (RW) drove over to my friends Mercury dealership and we tried the prop on both our boats. I have a 2001 Redfisher with a 2012 Pro XS 115. I was at 5680-5700 rpm's with the fastest GPS p*** of 55.1 mph. I had about a half of tank of fuel. I was running a Laser II 21 with a max 5590 rpm and 50 -51 mph on gps. The prop is like a rocket out of the hole on both our boats. They do have a nice cup and seems to lift the boat better. Almost like a b*** boat up and running on the pad. RW could never blow the prop out. We took about a three mile ride up the winding Ocklawaha River in his HPX and it was unbelievable how well the prop held.