I designed these caps to protect Atari Jaguar controllers while they're in storage. The Atari Jaguar uses a common VGA like DB15 connector for it's controller ports. Unlike other hardware makers, Atari decided to have the male end of the connector on the controller plug. This can lead to damage when the controller is stuffed storage because the pins are exposed. These caps solve that issue.
The author hasn't provided the model origin yet.