- For use with the KX-TVA50 only
- Supports DPITS integration only
- Expands the port capacity of the system by 2 ports
- Maximum two cards per KX-TVA50 system
- Panasonic's 2 port expansion module- Adds 2 ports to KXTVA50 voice mail system- Used only on digital DPITS (KXTD or KXTDA) integration- Maximum two cards per useKX-TVA503