I'm a DIYer for over half a century. I'm also a huge "value shopper" who wants a big bang for the buck. This may be the single greatest value in 50 years of buying tools. If you are like me, you've never used a jackhammer: First, even though I too often don't use safety stuff, DO wear safety glasses and hearing protection and, especially if you're sensitive to dust, a dust mask. Let the tool do the work. Let its weight do the chipping; don't force it or push it.
Amazing deal. I had to cut through some concrete stairs and part of a slab. This hammer did it effortlessly. Some of the concrete was more than a foot deep, and a sledge hammer wouldn't touch it. With this, it just crumbled. Saved hours of work and many blisters.
I'm using the jack hammer to take down a chimney in a house I'm renovating and it's doing a great job. It's built well and is standing up to the punishment it's being asked to take.
Plenty of hammerjack power to break-up concrete. I used this hammerjack to break concrete around several embedded wood fence post in my driveway. It punched the concrete with power and precision.