Bt bt8600 call blocker twin product overview bt bt8600 call blocker twin 083158 this twin bt cordless phone with answer machine features a one touch call blocking button that blocks up to 1000 numbers this option is only applicable with the caller display service which may incur an extra charge the answering machine has up to 60 minutes recording time to allow room for plenty of messages the phone also features a do not disturb mode and saves up to 200 contacts call blocker allows calls f