I think these take 30 GPM. I ran one on a 290 Komatsu that had JD motor on the top of the counter wieght to run a big pump just for the cutter head. We'd take 2 300's and put them side to side where they would over lap the swing rdius by a foot each. they had a rotator that allowed them to rotate 180 degrees to match your mowing. You can take care of alot of ground in a day. One day I had to stop and fix a leak and my friend Jerry was still mowing and there was alot of RR iron laying aroun Wed walk it over them mow. I looked at Jerry's machine about that time a racket and sparks and more racket came about. WHen he got eveything stopped we found an old forked tree stump with a 4 foot section of 90 pound rail grown in it. by the cut he had in it he had cut six inches off of it in that short time. He was leaking fluid and also missing alot of carbide teeh.