The bt 4000 big button has large buttons making it not only practical for elderly customers but also an aid to sight hearing and dexterity impaired customersfed up with sales calls interrupting you at home the new bt 4000 big button brings you unique functionality to block nuisance or unwanted calls its call management feature puts you back in control by enabling you to choose the calls you want to take and those you want to blockdesigned in the uk the bt 4000 big button offers you a larg