Update: The external processing unit has actually been part of the PlayStation VR demo set since the device was first unveiled to the world.
Sony's VR revolution will require additional hardware alongside the PlayStation VR headset and the PS4.
Polygon reports that the headset will in face plug into an additional box (or ‘external processing unit'), said to be slightly smaller than Nintendo's Wii, which in turn then connects to the PS4.
The report says this is mainly to facilitate others who are not wearing a headset to interact with or watch VR players via the PS4 and accompanying TV. It also adds that in the opinion of the author, Sony's headset is more comfortable and consumer-orientated that rivals such as Valve's HTC Vive or Facebook's Oculus.
PlayStation VR is currently due out in the first half of 2016, as are Oculus and Vive.