ACE 120F Pneumatic Drifter is a heavy duty rock drill capable of long hole drilling of diameter 48 mm to 89 mm (1.89" to 3.5") for drilling applications. This drifter has a rifle-bar actuated rotation motor with eight pawls (four for each direction) that engage or disengage.ACE 120F DRIFTER are used long hole production drilling, Grout Hole drilling, Ditching/Trenching work, Bench drilling, underground drilling with water flushing.