First reviewer. But long time Revain Prime Customer. Just felt the need to review this Boss Hog! I'm a geologist and I don't think there are many people who can put a tool like this to a harder test than I can and my final conclusion is that this thing is an ANIMAL! Now I live in Kentucky, which has a diverse geology. As such, the experience of using this tool in a large metamorphic belt or magmatic complex may vary, but here I go. For the test I used a 1 inch diameter chisel. I drilled 5 holes (each 6 inches deep) in about 20 minutes through three large (15-20 pounds each) hard crystalline quartz nodules with 5.0 aH vapor. batteries. It's moderately light (15 pounds with racquet and batteries). Light enough to throw in a backpack and take a few miles to the field. Use this along with some wedges and spacers and a jackhammer and strategically splitting large sections of rock will be quick and easy. Great workmanship, excellent durability! Every hard rock geologist should have one!