Adjustable countersink drill bit with a free spinning depth stop. The depth of the pilot bit and countersink bit can each be adjusted independently. Depth stop rotates freely, so it will not mar a finished surface. The Centrotec shank is designed for use with the Festool Centrotec System, as well as with all standard or keyless chucks for no-slip performance. The Centrotec System was designed to provide a seamless transfer of force, eliminating bit slippage or marring of the drill bit. The weight of the drill is reduced by nearly pound, and the length is reduced by nearly 1-1/2 inches with the Centrotec System. Most importantly, the Centrotec system offers a quicker and more secure means of bit change than any other quick-change chuck system. Replacement pilot bits (494445 & 494446) and grub screws (090040) are available separately.