The Siemens 6ES7798-0GA02-0XA0 is a spare-part AC/DC power supply unit designed for the SIMATIC Field PG M3 programming device. It ships without a line cable, so you will need to supply the mains cord separately.
What this means for a field service swap
If you are replacing a failed PSU in a Field PG M3 on a live production line, this is the correct Siemens spare part number. The AC/DC input stage is built for the PG's internal rail; verify your site's mains voltage and connector type against the PG's existing line cable, since the replacement unit does not include one.