As the name states, this is a stainless spiral bone drill that creates the direction and depth path for the osteotomy drill. The correct direction M/D and B/L and depth is facilitated via the indirectly fabricated pilot drill guide. This drill is a contra-angle type with latch attachment. The drill is laser marked at 11, 13, 15mm levels and has a collar at the 21mm stop. This feature comes into play with the directional and depth pilot drill guide. This instrument is rotated slowly (400 RPM) in an up and down fashion to minimize frictional heat production in the bone. No irrigation is necessary, but helps bone debris removal.