We got tired of breaking everybody else's bits in our PowerHead Screws so we developed our own bits which are nearly indestructible. 

The Wiha impact bits are now available in 4 drivers (T20 Torx, T25 Torx, #2 Square, & Phillips). It has up to 30 times better performance over standard bits and is impact rated. Standard 1/4" drive. These are special chrome-vanadium molybdenum tool steel with an enhanced bi-material torsion zone.