Quick-change mechanism enables lightning-quick bit changes</br>5/16-inch shanks for increased durability</br>Multi-cutter countersinks produce a superior finish with less chipping</br>Easy 1-handed release for quicker changes</br>Kit contains: drill drive holder?? drill drive connector?? (three) countersink bits?? (four) replacement drill bits and heavy-duty container?? (three) screwdriver bits</br></br>Amazon.com</br></br>The DEWALT DW2735P 12-piece Drill Flip Drive Kit features high-quality bits with durable 5/16-inch shanks. The black oxide drill bits produce less walking than other drill bits for more precise?? accurate drilling. The multi-cutter countersinks produce a superior finish with less chipping. The innovative quick-change mechanism ensures quick and easy one-step loading.</br><br/>http://www.amazon.com/gp/product/B000051WR8