SecureSleep Baby Monitor For parents who want to make sure their little one is as comfortable as possible during naps and bedtime there's the Summer Infant SecureSleep Audio Monitor. This monitor not only lets parents keep a close ear on baby but acts as a room thermometer and soft glow nightlight. The soft glow of the baby's unit changes colors signifying if the room is too cold, too hot or just right. 900 MHz digital technology for a private transmission 650 range Red = too hot, blue = too cold, yellow = just right Both units have large LCD screens with F or C option