I should also mention that I bought the heaviest duty 5' Bush Hog mower for my 40 HP tractor and it took so much more power just to operate its mechanism that I must now mow higher and slower than with the King Kutter mower that I replaced when it was "used up". I would probably been have better off with their medium duty mower, but the heavy duty one that I bought is very rugged and will likely outlast me. It has a slip clutch which has never been adjusted, but I always keep it in the barn. It has tangled with many immovable objects... The diesel tractor bogs, but only the swing blades have been affected. It needs a sharpening this Winter once again. Trail mowing has its hazards.