Features High Efficiency --- The spiral groove with a central bit will quickly remove debris from the hole, which will prevent the build-up of rock chip traps and improve drilling efficiency. Rational Structure --- The hole drill is structurally sound and the chamfer is made of steel for aesthetic durability and superior quality and detail. Alloy Steel --- The hole drill is made of alloy steel for good chip removal, bending resistance, wear resistance and durability. Adjustable Limit --- Our countersink bit has an adjustable limit that will not punch through the plate and is easy to use. Wide Application --- Countersink bits for countersinking and opening holes for screws in wood, plastic, soft metal, fibreboard, aluminium alloy, etc. Specification: Item Type: Adjustable Depth Countersunk Bit Material: Alloy steel Colour: Silver Specification: Approx. 3.5 x 8mm / 0.14 x 0.31in Use: For countersinking and opening holes in wood, plastic, soft metal, fibreboard, aluminium alloy screws, etc. Package List:1 x Adjustable Depth Countersunk Bit 1 x Wrench1 x Hex Wrench1 x Set Screw1 x Storage Box Package List 1 x Adjustable Depth Countersunk Bit 1 x Wrench 1 x Hex Wrench 1 x Set Screw 1 x Storage Box