: Automatically blocks internet access if the VPN connection drops, preventing data leaks.

While does not officially use a ".opk" file format for its standard applications—which typically use .exe (Windows), .dmg (macOS), or .ovpn (manual OpenVPN configurations)—the .opk extension is commonly used as an "Open Package" for OpenDingux handheld gaming devices like the RG350.

Whether using a manual configuration or a lightweight extension, these features are central to the NordVPN experience: