an extension telephone
 

* 1.off premises extension (opx)

2.on premises extension

English Related Words* aiff extension

* american telephone and telegraph, inc.

* analog telephone exchange

* anchor line extension kits

* another telephone line

* answer the telephone

* arj extension

* army extension courses

* asm extension

* automated telephone ordering (ato)

* automatic extension

* automatic long distance telephone system

* bak extension

* barrel extension

* bas extension