Starrett A3-6 Ulti-Mate Hole Saw Arbor With Pilot Drill And One Of Each Of The Standard Hole Saw Adaptors. ULTI-MATE from Starrett offers super fast, tool free changes between different diameters and types of hole saw, without adjustment of the drill chuck. Removal of cores from a hole saw after a cut is also much improved by the rapid release of the hole saw from the arbor.