Features 20 percent thinner wall construction - faster cutting due to less material being removed for the same size hole. Duel alternating tooth geometry - more aggressive cutting as well as increased chip ejection.Cuts up to 15 percent faster.Proprietary steel and 3 hardness zones makes the bit less susceptible to breakage.One Centering pin size for all 2" depth cutters.Weldon shank, fits most small magnetic drill presses.Ejector pin sold separately.Kit includes 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8", 15/16", 1-1/16", (2) Pilot bits and case