I don’t even know what they look like? A small DVD?
They used to be 12 inch vinyl records with extended-in-time
versions of popular songs that were mostly used at dance
clubs. The radio version of a hit song could be 3-4 minutes
long. The Extended Play ‘EP’ disco-club version could be up
to 25 or more minutes long.
i.e. Soft Cell’s - Tainted Love.