Audioline PowerTel 680 Combo. Volume control: Digital. Phonebook capacity: 200 entries. Display: LCD, Display number of colours: Monochrome, Backlight colour: Orange. Frequency band: 1.88 - 1.90 GHz. Power supply type: 2.4 / 6 VDC, Battery type: AAA, Battery technology: Nickel–Metal Hydride (NiMH)