IF you need isolation don't go the ps210 way, it isolates a little more than a conventional earbud. I even bought the ps 210 to use in the lab so I can hear my colleagues.
Thank you for your reply about the CK7's
What set of double (or triple) flange-tips would work with the Phiaton 210's? You mention in your review that the poor isolation almost makes a flange purchase necessary. I shop on Amazon 99% of the time if that helps.