The B30-CB countersink drill bit is offered as a compatible installation tool for our 30mm Brass Concrete Markers.  The B30-CB 12/33mm drill bit facilitates the correct installation of 30mm brass markers, such that the marker ends up flush with the concrete surface.  Simply drill a hole with our countersink drill bit, insert the included expansion plug, and tap the marker into place. This bit can be used with any SDS chuck and some 1/2" chucks.