AT&T Corded Trimline Phone With Caller Id (White) The AT&T TR1909 trimline with caller ID/call waiting can be used either in tabletop or wall installation position, and requires four AAA alkaline batteries (not included) for battery-powered functions. The telephone can still operate with limited features when there are no batteries installed. The TR1909 also features a 13-number memory for fast dialing and has a call log which can store up to 80 additional numbers with names. This telephone has a caller ID feature which supports caller ID with call waiting service.