Leadingzero writes “What we have here is your typical NES controller converted into a Bluetooth handset suitable for use with mobile phones and VOIP software on Bluetooth-enabled PCs. The controller itself is an actual NES controller. The plus-pad has been hollowed out and houses a speaker to listen to conversations. A discreet little hole next to the “A” button allows sound to travel to the internal microphone.” Link.
NES Bluetooth Handset