Universal type for both positive and slotted drivers Internal retainer shape makes it easy to check when tightening is completed. Manufacturer Model Number: PF11-M3-0; Screw Nominal: M3X0.5; Minimum Plate Thickness: 0.03 inches (0.92 mm); Hole Diameter: 0.2 inches (5.56 mm) (±0.08 mm); Material: Aluminum (Knob), Steel (Retainer), Screw/Spring (Stainless Steel)