1. Concrete Hollow Boring Machine 2. gasoline engine 3.man-made PCD drilling bit 4.max. boring depth: ... material, ceramics,glasses and rock. 2. Characteristic:Use imported gasoline engine, drive conveniently, run reliably, operate simplyNo need electric powerequipped with ... ~1200r/minDrill type: man-made PCD thin drilling bitDrive: gasoline engine (power: 5.5HP, speed: 3600r/min)