pete i bought 2 lately for my rst.
1st one came with copper washers,2nd one never.
i bought 2 cos 1st wouldnt seal and it split after i had to tighten it tooo much lol

you can buy em seperate mate.
my local motorfactors sell em on them racks called oddbits or something.
the spinning rack with fuses,jubilees,connectors etc on.