Festool Ce Countersink Dr. Bit 4.5mm - 4.5mm adustable countersink drill bit with a free spinning depth stop for use with the Centrotec system. The Centrotec shank can be used with all three-jaw chucks for no-slip performance or in conjunction with Festool's Centrotec chuck system. With the Centrotec design there is a better transfer of force with no chance for bit slippage or marring of the drill bit. Reduce the weight of the drill by nearly ?? pound and the length by nearly 1-1/2?ö with the Centrotec system. Additionally the Centrotec system offers a quicker way of changing bits than a keyless chuck with less run out.3.5mm fully adjustable countersink drill bit with depth stop.Depth stop is in free rotation so it does not burn or mar your surface.Replaceable bit system for economic concerns.Long precision milled hex shank for secure clamping and no wobble while in use.Fits either Festool Centrotec chuck or standard chuck.