HLS-3 HEICO Fastening Systems HEICO-LOCK Washers , Manufacturer Part#: HLS-3 , Manufacturer: HEICO Fastening Systems , Brand: HEICO-LOCK Washers , UOM (Inch or Metric): Metric , Material: Steel , Finish: Zinc-Flake Coated , Bolt Size: #5 UNC (M3) , Inside Diameter: 0.130 Inch (3.40mm) , Outside Diameter: 0.280 Inch (7.00mm)