Robust enough to cope with the challenge, the Stihl BT121 earth auger is capable of drilling holes up to a diameter of 350mm (14 inches) via a rotating speed of 190rpm. The powerhead which weighs 9.3kg (20lbs), has been designed specifically for use by a single person and has been constructed with safety in mind. The QuickStop®™ drill brake immobilses the tool in the event of any jam.