You may also be interested in the following product(s)
NEC SL1100 Expansion KSU (1100011)
A maximum of three (V3.5 or higher) additional 1228ME EXPs can be connected to expand the system capacity of the 1228M KSU. Although similar in shape and size as the 1228M KSU, the capabilities are not the same.
SL1100 Expansion Key Service Unit (0x8x4) provides
- 8 Digital Station Line Ports
- 4 Analogue Station Line Ports