Yakamoz Colorful Dream Catcher Dreamcatcher Leather Flip Card Slots Wallet Stand Case for LG Optimus F60, LG Transpyre, LG Tribute LS660 with Free Screen Protector & Stylus Pen 5 piece set includes bits for drilling pilot holes for screw sizes 6#,8#,10#,12#, and 14# Special designed steel counter sleeve countersinks or counter bores pilot hole, Drill and countersink for wood screws without changing bits Adjustable counter sleeve depth with Allen wrench. Standard hex shank is quick change compatible Drilling length can be adjusted for various length screws simply by loosening and tightening the setscrew. Suitable for bore metal, PVC, wood, plank, aluminum alloy or plastic board.