Pet Shop Boys – It's Alright

Hand-written "UNKNOWN DANCE MASTER CIRCA 1990"
Argentina metal 'mother' stamper for side A of the 12" single commercial release.
Maybe this is the only surviving one in existence especially as they were often destroyed once the commercial release was pressed.
Unlike stampers the mother has grooves and could be played like normal vinyl.

Additional info on stampers:
Plating refers to the process of making metal stampers from Lacquer. The Lacquers are silver coated and electroplated to make a negative image of the record in the 'male & female' sense, meaning the grooves in the plates are raised where the grooves in the records are etched.
Plating then involves making 'Mothers' from the stampers. 'Mothers' are a metal version of the finished record and are limited to less than a handful for any given release. So, a stamper is a negative image & not playable, the mother is a POSITIVE image & IS playable.