You are Buying a Brand New And factory Sealed Milwaukee 3-1/8 in. Carbide SDS-PLUS Masonry Core Bit Model # 48-20-5235.... core bit sizes using one adapter. The spiral core body design minimizes friction in the hole and aids in dust removal during the application. Core bits cut with the outer edge only, therefore the operator must remove the inner core continue drilling for holes deeper than 2". Asymmetrical carbide teeth for up to 20% faster drilling speeds. Centering bit for easy spot drilling. Two-piece design for maximum versatility. Spiral core body design to minimize friction and increases dust removal