Review on 🚀 Revolutionary Feather Concrete Marble Granite Splitting solution - Unleash Incredible Efficiency and Precision! by Robert Howell

The blocks are solid with even tapers and strong o-rings (required if the rock breaks to hold the pieces together). Light, steady, successive taps easily shattered a solid 8-inch-thick concrete slab that firmly withstood a good 60-pound electric hammer. not perfectly "flat" on mating surfaces, but drill bits are polished with rock or wet-dry paper and work either way. I read somewhere that they're a little brittle - that's because they're brittle hard, but you don't need a big hammer to use them and unless you hit them from the side they last a long time. If you need them, they cost more than the price! (PS - buy a 9/16 ".)