The Fire Telephone (FB7) safety sign has a red telephone on the square shaped safety sign.
 
The sign indicates where fire telephones or amplifiers can be located and is often used in conjunction with one of the following safety signs:
Location Of Fire Fighting Sign
Location Of Fire Fighting Sign (Diagonal)
The fire telephone safety sign is also available as a Photoluminescent (glow in the dark) sign as a single safety sign or as a combination of more than one safety sign.
Refer to the Photoluminescent section for various combination options. 
SABS standard safety sign