These fender washers are great for mounting fiberglass fenders, aluminum panels, etc. as it spreads the load over a greater surface area. They are CNC machined in-house from domestic 1.25" OD 6061-T6 aluminum and are available natural or anodized black, gold, red or King blue. They are designed to be used with a 1/4" flat head screw with a 82 degree taper under the head. We've been supplying these to the offroad industry for 20+ years. These aren't cheap imports or copies like you'll see online. We also offer a 10pk kit that includes the stainless screws and weld-on tabs.