The First Years Crisp and Clear Audio Monitor, with 2-Receivers. Receivers work when plugged in or with batteries. Has a good audio range as 2 stations. -Lightweight, portable monitor gives you peace of mind when you're away from the nursery. -Two receivers to place in two different rooms, or let each parent have their own -Sound level lights let you see baby's activity level -Low battery and out-of-range alerts -Comes with belt clip and two AC adaptors -Baby unit can be wall mounted. From smoke free home.