Transmitter can be set to 4 different channels allowing multiple cameras to be used with one receiver. Will not be affected by 2.4 GHz cordless phones, wireless networks or microwave ovens. 1-1/2 mile line of sight requires the use of a high gain directional antenna. With the included antenna expect 2000 to 2500 feet line of sight. Transmitting through walls, trees or other obstacles will reduce range, concrete and metal obstacles reduce performance the most.