Grandstream Networks GRP2612. Product type: IP Phone. Product colour: Black. Handset type: Corded handset. Dual-tone multi-frequency (DTMF) modes: In-band. Out-of-band. SIP info. Password protection type: Supervisor. User. Number of lines: 2 lines. Volume control: Buttons. Display diagonal: 6.1 cm (2.4"). Display resolution: 320 x 240 pixels