Muirhead-Pametrada Wave Analyser type D-489-GM, serial no.349364 in fitted wooden case, plus Supply Unit type D-489-GS serial no.347228 also in fitted wooden case, plus the following accessories (stored in the base of the power supply case): headphones, connecting cable, mains lead (without plug) and input lead, made by Muirhead & Co Ltd in about 1960 Muirhead-Pametrada Wave Analyser type D-489-GM 1960-1964