... ,YN30A,YN30E,YN27,YN27C,YN27T certificate:ISO9001,CE super air /petrol /electric rock drill from chinaFeatures 1. The Internal Combustion Rock ... hand-operated rock-drilling tool, composed of a small petrol engine, an air compressor and a rock drill. 2. During operation, the rock ... the machine itself. 3. It carries easily with the main engine weighing only 30kg. It is suited to work on high ...