e/Multi-Line Extension telephone

Information
has gloss	eng: A Multi-Line Extension, or MLX telephone, is a no-longer-manufactured series of digital telephone used with several PBX systems sold throughout the 1980s and 1990s by AT&T. This series is notable for the sheer quantity of devices operating in the field, and for its after-market continuing long after the manufacturers stopped making them. Their popularity has also contributed to the existence of a sizeable refurbishment market.
lexicalization	eng: Multi-Line Extension telephone
instance of	c/Western Electric telephones