The Heart-to-HeartTM Prenatal Listening System from Summer Infant is a wonderful way to hear and share the precious sounds of your unborn baby's tiny heart. The unit does not use ultrasound technology, is safe and non-invasive. It is the perfect way to start the bonding process with your baby. Recording cable allows you to record the heartbeat to your home computer to share with family and friends. Heartbeat sensor allows you to start listening to your baby's heartbeat, hiccups and kicks starting around the middle of the second trimester.