Floor-standing telephone exchange made by Allmänna Telefonaktiebolaget L. M. Ericsson
circa 1920
PMBX Telephone Exchange
circa 1950
PMBX 3+9/12 Manual Exchange
1930
CB 10 switchboard made by Peel Conner
1912
PMBX 2+4/6 Manual Telephone Exchange
1930
PMBX 2+4/6 Manual Telephone Exchange
1930
PMBX 1+3/4 manual exchange
Manual telephone exchange used at ICI
1947