NGM-Mobile Billy. Display diagonal: 50.8 mm (2 "), Display resolution: 220 x 176 pixels, Display: TFT. Compatible memory cards: microSD, Maximum memory card size: 2 GB. Data network: GPRS, GSM, GSM bands (primary SIM): 900, 1800, 1900 MHz, GSM bands (secondary SIM): 900, 1800, 1900 MHz. Headphone connectivity: 3.5 mm. Ringer type: MP3, Audio formats supported: MP3