British Telecom Synergy 5500 Twin. Dialer location: handset. Volume control: Digital. Phonebook capacity: 250 entries. Display: LCD, Display number of colours: Monochrome, Backlight colour: Blue. Base dimensions: 100 x 125 x 44 mm, Handset dimensions: 49 x 25 x 160 mm, Handset weight: 110 g