Post Office answering unit. Photo caption: The new Post Office automatic answering unit, which can be rented from the G.P.O. by telephone subscribers. A 20-second message is recorded by speaking into the telephone mouthpiece, and this message is played back to callers. The unit is made for the G.P.O. by Sontranic Limited, and the case, of colour and shape to match the new G.P.O. 700 grey telephone set, is made from reinforced Bakelite polyester resin by K & C Mouldings (England) Ltd., (Buntingford, Herts). This item is part of the MoDiP BXL collection.