Board-to-board connectors that may provide durable and reliable connections, may save board space, and may be easy to manufacture. One example may provide board-to-board connectors that provide durable connections by providing a seal between board-to-board plugs and receptacles. The seal may be an O-ring, gasket, or other seal. The seal may protect contacts on the board-to-board connectors from exposure to fluids, such as water or other corrosive fluids. This seal may provide a level of redundancy with one or more seals protecting a device from external fluids, such as a seal at or in the device enclosure.