Warranted for life through any Mac dealer or the company themselves, no matter what size, unlike every other company. Slow speed is cobalt, works like a charm. The item “MAC 29 piece Cobalt grade drill bit set” is in sale since Monday, September 05, 2016. This item is in the category “Home & Garden\Tools\Power Tools\Drill Bits”. The seller is “matthewoo_65″ and is located in Pawling, New York. This item can be shipped to United States.