Lanier LF215 - Manual (Page 31)

G ETTING S TARTED 1.16
N OTE : In the United Kingdom, if a three-wire type (SHUNT-wire,
older equipment) telephone or answering machine is connected to
the EXT jack on the machine, the external equipment will fail to
ring when receiving an incoming call as the machine is designed to
operate with the latest technology. To prevent this incompatibility,
use two-wire (newer equipment) telephone or answering
machines.