Intercom doorphone for double rooms, two hundred talk distance, more convenient. Operation distance 200m, 2-line connected, strong signal and clear communication. Easy to install, DIY installation, can be placed on the desktop or hanging walls. Energy saving and no current consumption while not work. Practical and convenient, widely used in offices, warehouses, families, etc. Specifications: Battery: 1.5V (each unit need 4pcs AA batteries, the batteries are not included) Working Currency: Bell Rings Grade: 70DB(0.5 meter distance) Connection: by wire RVV2 (the cable is not included for this listing) Size: . 22.2 x 8.7 x 7.3cm/8.7 x 3.4 x 2.9inch Note: When using, you need to connect the radios of the same color (within a range of 50 meters, it is best to use RVV2x0.5mm line, and within 100 meters, it is best to use RVV2 x 1.0mm line) Note: The delivery is 2 pieces Colour: White Material: ABS Package Contents: 2 x Wired intercom doorbell Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.