2.92MM MALE - 2.4MM FEMALE RF MICROWAVE 50GHZ ADAPTER PREMIUM QUALITY AE1W16

No markings so we do not know the manufacturer, however the installation that these came from used only the best equipment - Agilent analysers, Carlisle cables, and other adapters from the same installation were all Huber & Suhner and Pasternack, so no reason that these would not also be of similar premium quality.

The installation these came from was at a European OEMs UK research and development lab which closed, it was a fixed test bed so these connectors have only been ever mated once or twice, so essentially like new.

Bargain for someone.