The makita 8406c is the upgraded version of the existing model 8406 it is packed with features to enable safe use when drilling with the larger dry diamond cores such as 2 variable speeds soft start switch constant speed under load torque limiter and makita39s anti vibration technology system it has drilling capacities in the percussion mode of 13mm in steel 35mm in wood and 20mm in masonry coupled with the dry diamond drilling capacity of 152mm the 8406c is a very proficient machine