What it is
The ABB 1SAJ260000R0100 is the MTQ22-FBP module; the title on record is 'MTQ22-FBP ETHER' and the part is listed under PLC Expansion Modules within the HMI Operator Interfaces path.
Where the class is used
MTQxx-FBP modules of this family sit on ABB operator panels as the Ethernet / fieldbus-plug expansion, so a panel builder wiring an ABB HMI station on a plant network sees this as the part that brings the panel onto Ethernet without re-architecting the HMI itself.