Features of Indoor Monitor: 7 inch TFT LCD display Plastic Panel, Fine Surface Fuel Injection Two way talk, monitor, unlock Wall hung installation Operating voltage: DC18V Operating temperature: -10 to +55 Display: 7 inch LCD color screen Wiring method: 5 +1 (RVV2 * 1.0 + RVV3 * 1.0 + SYV75-5-96) Ringing level: 60db Operation: Hands-free. Dimensions: 258 * 167 * 35mm.