I bought a pack of these from Amazon but only landed up using a couple. I think they are NOT OEM, but have the same dimensions as the OEM crush washer. I replaced the transmission fluid in my car, and used these crush washers, and they work well (no leaks).
Replaces part 90471-PX4-000.
Outside Diameter: 25.5 mm
Inside Diameter: 18 mm
Thickness: 1.95 mm
Price:
1 for 50 cents
OR
5 for $2
OR
10 for $3.5
OR
15 for $5
Please Note: These crush washers are for the transmission drain plug, NOT for the engine oil drain plug. I think it may also be used for the rear differential, but I am not 100% sure about this.