This little expansion module for the ZX Spectrum is a Adapt Electronics Spectrum RGB Output Module. Basically, it gives your 48k Sinclair Spectrum a nice and sharp RGB video output. RGB is miles better than RF, and even better than composite video. The RGB output put uses the same pinout as the Acorn BBC computers.
The picture is a little wavy in places. I will be replacing the electralytic capacitors to see if it makes any difference. You can download a copy of the manual from here : Manuals