This forestry mulcher is only 630 horsepower, but it processes like it has 7-800 horsepower. Picture a 7-800 horsepower horizontal grinder grinding whole trees and root balls, then put that grinder out in front of a tractor. Just as in a horizontal grinder, this rotor is belt driven and 3' in diameter; no hydraulic motors or high pressure lines. Totally belt driven, total transmission of engine horsepower to the cutting rotor, just like a horizontal grinder. And, yes, you can pick the head up to 6+ feet to get into large tree trunks, just like a hydraulic machine. Want to see it in person, call Jon Flournoy 843-412-3475 or jflournoy@seppimachines.com