Specifications:

• 4.3 inches, 272 x 480 pixel color display.
• The Avaya IP Phone J179 support up to 3 button modules, and each
  button module can take both Stand and Wall mount positions together
  with the phone.
• The J100 Expansion Module provides access to up to 24 buttons and lamps
  with ability to display 3 pages when a single expansion module is used.
• Each feature/line button has a red/green indicator.
• Pre-configured background or screensavers are available to match the base phone.
• Power is supplied by base J179 (PoE class 2). If 3 expansion modules are attached to J179, then an external 5 volt power supply is required.
• Supported on J179 with both H.323 and SIP software.