Harrison 4032 is a 40-channel analogue audio mixing console which was bought by Polar Studios in 1978. Three ABBA albums have been recorded with this console: "Voulez-vouz", "Super Trouper" and "The Visitors". Among other productions done in this console can be mentioned Led Zeppelin's "In Thought the Out Door" and Genesis' "Duke".
The console was the first of its kind with outputs to the headphones and was custom made for Polar Studios. This was something completely new: each musician or singer could hear himself and adjust the listening after his own needs.
The 8 white buttons under the 24 grey ones are the ones which were used. The console was later furnished with additional 16 channels.