Kitchen P trap washer

[Al@n]

Need to replace the P trap conical washer under the kitchen sink.

Local plumbing merchants only had one in stock which is not the correct match, it is not suitable as its too thick.

Pic attached, left is the one I purchased from the plumbing merchants, right is the one I require.

Struggling to find the washer I require online, any ideas, where I can purchase the exact washer I require which appears to be a 'thinner' version

 

[Exedon]

Few wraps of ptfe on original?
I'd just replace mcalpine do a good range decent quality.

 

[Al@n]

Few wraps of ptfe on original?
I'd just replace mcalpine do a good range decent quality.

It is a double kitchen sink, will give PTFE a try, thanks