The Bachmann Keystone module 917.120 USB-A / A can be retrofitted or replaced quickly and with minimal effort. The USB connection requires an installation depth of 85mm and has a USB-A socket on the front and back. The module can be screwed into a table socket from the CONFERENCE, CONI, DESK 1 or DESK 2 series, for example in conjunction with a Bachmann Keystone frame 917.000 or 917.001.