BT 4600 Cordless Telephone with Answering Machine - Trio With BT's advanced call blocking technology, a built-in phonebook and 60-minute answering machine, the BT 4600 makes it easy to stay in touch with your favourite contacts. You can block up to 1000 nuisance caller numbers to only accept the callers you know, and with a 200 name and number phonebook, there's enough storage space to save all your friends and family.  It features a hands-free option for taking calls when you're busy, a large digital display which makes it easy to make and take your calls. Answering machine - Records up to 60 minutes of messages so you can catch up on any calls you miss. BT Premium Call Blocking*  - Let through saved numbers and block nuisance numbers at just the touch of a button so you don't have to deal with repeated hassling callers. Digital phonebook - Stores 200 names and numbers so you always have the numbers you need close to hand. Cordless Headset volume adjustment: Yes Ringer volume adjustm