It fits under the mattress of the baby and alarms you when the baby stops moving or is absolutely still for 20 seconds. Some models available also come with audio monitors installed. These come with a portable parent s unit that sends you the alarm and allows you to hear your baby s activities. What are the things that you should consider? Also, the family budget in choosing a monitor must also come in mind. If you are decided on getting the best and if you have the means to splurge on high-end monitors, then there is absolutely nothing wrong with that. But if you are on a tighter budget, many good monitors are available in the market for almost just as good the quality at more economical prices. This is the descendant of the basic uni-directional system used by basic and usually old monitors. These new types of baby monitors however have been integrated with new technology. Instead of just being able to hear your baby, you can now actually talk back to him or her. There are even some devices that will let you send commands to the baby s device to play different music to hush him or her back to sleep. Range The size of your house, as well as the distance of the nursery from your bedroom or other vital parts of your home need to be taken into consideration. If you live in a small apartment or if your baby's room is only a couple of rooms away, then virtually any type of baby monitor will suffice. On the other hand, parents who own bigger houses or live in multi-story residences require a device that has a longer range. Video baby monitors make use of cameras instead of just the usual transmitter with microphone device. A camera or a number of cameras are installed in the baby s room and live video feed are transmitted to a TV or LCD receiver. These video devices can either be wired or wireless devices. The most basic application of a wired video baby monitor is to provide live video feed from the room of the baby to the room of the parents. Mobile baby monitors make it possible for parents to keep tabs on their infants without the necessity of staying awake or standing outside the nursery door all night. A typical baby monitor set consists of two parts: a radio transmitter and a portable receiver. The radio transmitter must be positioned 8 to 10 feet away from your baby's crib.