DeWalt Blue-Tip screwbolts are a one-piece heavy duty concrete screw with ETA Option 1 approval on diameters 10mm to 16mm. The Blue-Tip screws are simple to install and provide a strong, secure hold for high load applications and small edge distances, making it the preferred choice for a fast, reliable installation into a variety of substrates. The anchors are designed with a dust relief thread that allows for low installation torque, are fully removable and are designed to resist structural and non structural loading in cracked and uncracked concrete, Features: ETA Option 1 approved for cracked and uncracked concrete Approved for small edge distances One Piece design for easy installation Dust relief thread allows for low installation torque