There is increased awareness of dust extraction, so if you're drilling concrete get the best solution with the Makita SDS-Plus Hollow Dust Extraction Drill Bit. The Bit features dust extraction ports so when used with a rotary hammer and dust extractor (sold separately), it offers drilling and hole cleaning in one step, and reduces airborne silica dust. Makita SDS-Plus Hollow Dust Extraction Drill Bits are an OSHA Table 1 compliant solution when used in conjunction with an approved control dust extractor vacuum (sold separately). The Bit features 3 cutting edges for maximum performance, rebar resistance, and more accurate holes. There are 3 cutting edges that are engineered to help prevent cracking of the surrounding concrete, and 3 supports between each edge to provide more accurate holes. Added features include a self-centering Tungsten carbide tip to help drive the bit straight.