GENUINE MICA high voltage insulating washers
Based on the “average puncturing voltage” table for the mineral mica, from the American Institute of Electrical Engineers website, each washer should withstand in excess of 8,000 volts! Of course, you can “stack” multiple washers for increased voltage ratings.
Outside Diameter: 0.875 inch
Inside Diameter: 0.250
Thickness: 0.0085 inch to 0.0095 inch