Designed for hard jobs, the Billy Goat Outback Brushcutter and can cut a clear path through the densest brush, grass and weeds over 8 feet tall, saplings up to 3/4" inch in diameter and other problem vegetation at the rate of 2/3 acre per hour. This type of mower is also known as a Bush Hog or BushHog or a forestry mower or a walk behind brush mower or replacement for sickle bar mower. Not a flail mower. Sometimes called a clearing mower or walk behind hay cutter or brush cutter or slope mower or brush hog or field mower.