IRWIN® Cordless Multi-Purpose Drill Bit Set, 5 Piece 4-10mmThe Irwin Cordless Multi Purpose Drill Bits have been designed for cordless low min multi purpose drilling. In tests they produced between 90 129% more holes per battery charge than leading competitors. They have a four facet ground carbide tip for lower drilling pressure and better centring and allow for combined drilling into wood and brickwork: the Cordless Drillbit is excellent for such drilling jobs where you drill through wood into brickwork.