Features Streamlined design with handset Digital TFT screen with high resolution Touch sensor button operation Handset answer mode Staircase light control via RLC unit Telephone entry extension via GSM unit Compatible with all DT outdoor & Indoor stations Specification Power Supply: DC 20~28V Consumption: Standby 0.17W; Working 3.5W Screen: 4.3 inch digital color TFT Resolutions: 480 x 272 pixels Video Signal: 1Vp-p, 75Ω, CCIR standard Wiring: 2 wires - non-polarity Dimension: 186(H)x191(W)x37(D)mm