The BT Diverse 7400 additional handset is a versatile cordless unit, to be used with the Diverse 7400 base station. This BT telephone can store up to 200 numbers and 30 names and numbers for the caller ID function, so you can see who is calling you. When fully charged, the BT Diverse 7400 lasts for up to 120 hours on standby battery, and provides up to 12 hours of talk time.