Self-drilling drywall anchor Fischer Duoblade for quick and easy installation in drywall. No additional tools are needed except for a Phillips screwdriver. The self-drilling triple tip is extremely resistant to high temperature (due to friction) and guarantees secure placement. It can be used with wood screws, chipboard screws, or sheet metal screws with a diameter of 4-5 millimeters, as well as with screws of the same diameter with an angle, hook, or ring.