Just retired from 37 years as a full-time firefighter in California. I've had many long hours with the tool on wildland fires. Yes, it's called a brush hook though that particular model was also called a strap hook due to the lighter-weight construction. The original models were much heavier and tended to make nasty cuts on the legs of someone who was not familiar with the aerodynamics of the beast. It's been quite a few years since I've seen them in normal use. They were replaced (Thank God!) by the chainsaw. That picture brought back many memories of climbing hills and cutting brush for days on end.