With the Bosch pro Ceramic Dry DrySpeed x-lock diamond core set, you drill cleanly and reliably through soft wall tiles to very hard porcelain and stoneware. High-grade vacuum-brazed diamond grit eliminates the need for water cooling setups while preventing tile cracking and chipping. Thanks to the tool-free x-lock mounting system, you can click each bit onto your compatible angle grinder in seconds. Supplied in a sturdy carry case, this 5-piece set contains 20 mm, 25 mm, 35 mm, 51 mm, and 68 mm bits for pipe passages and junction boxes, plus a 20 mm milling cutter to reshape or enlarge existing holes.