The type of handset you are using is clearly labelled either underneath or on top of the telephone base.
Analogue handsets: ATL, BT Converse, Interquartz
- Siemens Optiset 'E' entry, basic, standard or advance
- Siemens Optipoint 500 entry, basic, standard or advance
- Entry phone handbook
- Digital basic and standard phone
IP handsets: Siemens Openstage 20