Siemens Optipoint 500 Key Module | 16 Key DSS ModuleThe Siemens Optipoint 500 Key Module is to add an additional sixteen keys to Optipoint 500 Standard Handset and Optipoint 500 Advance handset. Up to two modules can be plugged in per Optipoint phone.This module has 16 keys, which can be programmed on two levels.
