The AT&T TR1909B corded trim line telephone with caller id is ideal for people who live a lifestyle on the go. This phone conveniently allows you to see who's calling with built-in caller id, so you never have to pick up calls from strangers again. For added convenience, this phone has the ability to be mounted to a table or to a wall. This wall mountable telephone features handset and ringer volume controls, which allow the users to set the desired level. Mute, flash and redial options available in this telephone make it an easy-to-use gadget. The AT&T TR1909B corded trim line telephone with caller id is battery operated.