Oriented to the consistently positive reviews I decided on the lookout for high quality concrete drill bits, me for this drill. The delivery was, like Amazon, quickly and reliably. The aim was, mainly to put several holes with 6mm drill bit in a filigree reinforced concrete ceiling, to fix lamps, sockets and cable channels. After the first and second hole I was still excited and full of confidence for the next few minutes yet. 18 holes. After the 4th hole of the first drill smoked (there are 2 6 Boher in Set - who knows why). Okay, I thought've got one more. But this not even managed 2 holes so that I could not achieve my goal. I do not think I would buy this drill again. For bricks, aerated concrete, Poroton, limestone certainly well suited. For reinforced concrete I can no recommendation.