There are hundreds of monitors on the market, so choosing one can be daunting. Although monitors vary, they have the same basic components-a minimum of two units: one to transmit your baby's sounds, and one that stays with you so that you can hear if your baby is crying or fussing.
Additional features include: video screens, a moving lights-sound display, low power and out-of-range warnings, the option to use electricity or batteries, a talk-back function, and a temperature sensor. Some have a night-light function. With all these features available, your choice largely depends on your personal preferences and your budget. If your house is small, you don't necessarily need one.