There are many different baby monitors on the market, and all are very similar. Some baby monitors operate on AC and/or battery. Those models with a battery back up provide parents with added assurance in case of a power failure. Most baby monitors have a lighted display that coordinates with the level of sound the monitor picks up. The baby monitor is placed near the baby attached to the crib so that the sensitive transmitter picks up only the sounds of the baby, and not background noise. The babys sounds are then transmitted through the receiver to the parents as long as the receiver is within range of the monitor, which is usually conveyed to the parent by an out of range indicator light. Most models also come with a low battery indicator as well to let you know its time to change the batteries.
Baby monitors average $40 in price, some more, some less. It just depends on the manufacturer and what features the baby monitor has. You can shop online and compare prices and features of various baby monitors and buy there, or you can buy at most discount stores, or any store that carries baby products. There are also sights that compare models and are rated by consumer review which should help you decide which baby monitor is the best to buy. After all, you are entrusting the safety of your baby to the monitor when you are not right in the nursery, and you want to make sure that you purchase a reliable unit. Baby monitors make great gifts at baby showers also, you dont have to be the one expecting, but you can give the gift of added assurance to your friend or family member. Baby monitors can save babys lives.