Cordless phone with caller ID and speakerphone 2.4GHz frequency support, AAA NI-MH battery providing talk-time of 5 hours and standby time of 264 hours 50 phonebook entries and 5 redial memory Alphanumeric backlight display with alphanumeric keypad and night mode, Both KX-TG3611SXB and KX-TG3611SX are the same B represents the color of the Telephone Wall mountable phone, clock, alarm, any key answer, wheel navigation keys, light-up indicator with ringer alert, digital security code, paging and 7 ringer patterns, speakerphone Battery is available inside the product