The environmentally friendly GreenGrinder efficiently grinds, hones, and polishes concrete. It can be fitted with a water tank for wet grinding, and features a quick-change diamond system to ensure even diamond wear and quick field changes. Propane fuels a 22-hp engine, certified to meet EPA and CARB requirements with an emissions shut-down system and clean burning catalytic muffler enabling cordless operation. Green Umbrella Products. 870-917-2054.