Operation controls were separated into primary, secondary and tertiary functions. The primary functions – those you used every day – included programme selection, volume control and the off switch. They were easily accessible on the outside of the set. The secondary controls were under an aluminium panel. These included facilities for presetting 5 FM programmes; balance and tone controls; AFC (Automatic Frequency Control facility – which keeps stations properly tuned) and a mono/stereo switch. The tertiary functions, which were also hidden but easily accessible, were the connection sockets: you could make all connections for a record player, cassette deck, headphones and two pairs of speakers without moving the set.