Using this fetal heart rate monitor is easy. First, insert 2 AA batteries into the device (batteries not included). Then, turn it on and gently place the waterproof probe on your lower abdomen. Move the probe around slowly until you can hear the baby's heartbeat. You can switch between the two display modes by pressing the left button. Remember, the probe has high sensitivity and can pick up the heartbeat from 12 - 16 weeks of pregnancy. As for safety, the monitor is radiation - free, so you don't have to worry about any harm to you or your baby. When you're done using it, leave it alone for 60 seconds and it will turn off automatically. To keep it in good condition, store it in a dry and cool place. Don't expose it to extreme temperatures or moisture. Also, clean the probe gently with a soft cloth. The monitor has a validity period of 5 years, so you can use it with confidence throughout your pregnancy.