Video Intercoms Multi Apartment Door Entry Residential Intercom Rfid Doorbell Camera Electronic Doormanm 2/3/4/6/8 Units 7inch

7 inch Video Door Phone Intercom System for 2 / 3 / 4 / 6 / 8  Apartments 700TVL RFID Outdoor Camera / 7-inch Color Monitors Product Details There is a 4-wire system connection. Use a 4-core cable to connect the outdoor camera and monitor. The maximum distance can reach 100 meters. Different distances and cables of different diameters are used. Please check the following to select the corresponding cable. (We will send you a 5-meter cable for testing, for a longer cable, you need to buy it yourself or contact us before  when installing) Multiple Ringtones-Switch Freely The 25 polyphonic ringtones can be switched freely, which is elegant and beautiful. The ringtone and volume can be adjusted to meet your original needs. No longer have to worry about not being able to hear the sound or hearing the sound too loud.  Hands-free Two-way Intercom and Indoor MonitoringWhen the visitor rings the bell, the monitor will be activated and display the image outside. Press the answer