patpending said:https://www.ebay.co.uk/itm/10-X-METRIC-NITRILE-RUBBER-O-RINGS-3MM-27MM-SEAL-PLUMBING-TAP-HOSE-WASHERS/360755951161?hash=item53febaf639:m:mbXH14wArvySNvMmnQNuUsg
...or the above if you don't want to get creamed for a 10mm x 2mm o-ring @£10 from the stealers(for just 1)
Or will some still think they must be n-rated/magic o-rings at £10 a pop each.
https://www.design911.co.uk/fu/prod126866/Oil-Filler-O-ring-Porsche-996-Turbo-GT3---997-Turbo-GT3/
Indeed the genuine part is almost certainly a simple £1 O ring, but who is going to be brave enough to try the Ebay version ?