... ,YN30A,YN30E,YN27,YN27C,YN27T certificate:ISO9001,CE super air /petrol /electric rock drill from chinaFeatures 1. The Internal Combustion Rock ... a hand-operated rock-drilling tool, composed of a small petrol engine, an air compressor and a rock drill. 2. During ... used for rock drilling. It can be converted into a breaker or a hammer for breaking, digging, splitting and ramming by ...