The three PMAs are identical, but they have slightly different uses.
All three perform the same basic function of connecting a CBM port of an ISS module to an APAS-95 docking port of another module or visiting spacecraft.
For this purpose, the PMAs carry a passive CBM port and a passive APAS port.
The PMAs are pressurized and heated from the inside, and they allow for power and data communications transfer through docking rings and external connections.
The three PMAs are identical, but they have slightly different uses. All three perform the same basic function of connecting a CBM port of an ISS module to an APAS-95 docking port of another module or visiting spacecraft. For this purpose, the PMAs carry a passive CBM port and a passive APAS port. The PMAs are pressurized and heated from the inside, and they allow for power and data communications transfer through docking rings and external connections.
Pressurized Mating Adapter