magnetic sump plug washer

[krusty]

Doing a service on my engine and when ordering my bits from machine 7 I thought I would get one of there magnetic sump bolts.
It came with a black rubber washed about 5mm thick.
Ive never used a rubber washer before, always a copper one.
Just wanted to see if any body else is using these and if the rubber washer is ok, or should I swap it for a copper washer?

Thanks
Luke.

 

[67panel]

metal washer with rubber seal on inside?thats a dowty seal,sort of thing used to seal banjo joints on hydralic hoses.thats loads of presure so will seal your sump plug easy