Ultra Cutter 2-1/2" (63.5 mm) actual hole size. Lasts 10 times longer thanstandard hole saws. Precision-ground teeth cut smooth, burr-free holes with ease. 1/4" (6.35 mm) capacity. Durability and speed provide low cost per hole. Split-point pilot drill prevents walking - makes accurate hole placement easy. Spring-loaded slug ejector saves time. No tool required to change cutter sizes. Less chance of broken teeth because the saw body is machined out of solid, high-speed steel.