Golden Jet Impact Drilling Cutters from Enz USA can be used to remove stubborn deposits like concrete, injection cement, as well as calcareous and mineral deposits. It can cut out dropped liners and prep for a reline job. It can be used for pipe diameters from 4 to 24 inches. It comes with tungsten carbide and/or diamond-tipped teeth, and works with a percussion system of 600 to 3,000 impulses per minute, and up to 12 tons of impact force. It can be operated without impacts by means of a simple mechanical changeover. 877/369-8721; www.enzusainc.com.