name this part
 

yesterday i went to the shop and the guy had taken off my oil pan and said you need to look at the
he had pulled out acouple of small peices of coper thay had little holes in them and if you put them to gether the pices look like thay would form a circle and thay are 3mm thick
but the car runs great there is only 15,000 miles on the new rebuild and if it was part of some thing i doesent look like what ever broke is all there do you think it could be from when the other motor broke?

How wide? I'm picturing the copper crush washer that goes on the oil pan drain plug.
~Tom