I purchased this on Mercari and used it for about six months, placed under the mattress of a baby bed. It worked without any malfunctions, and I was able to sleep peacefully! I am selling it now because we have started sleeping in the same bed as the adults. There are no noticeable stains, and it is in a clean condition. I have also confirmed that it is working. Below is the product description from Amazon↓ --------------------------------------------- Babysense Home Baby Movement Sensor, Baby Monitor, Baby Alarm, Non-Contact Baby Sensor, Newborn, Wide Area Coverage Baby Movement Monitor, General Medical Device, Home Use, No App or Wi-Fi Required 【Home Use Product Utilizing Proven Technology】Babysense Home is a Class I general medical device. (Medical Device Notification Number: 13B3X10222001004) As the only officially certified Babysense product in Japan, it comes with a one-year manufacturer's warranty from the date of purchase. 【What is Babysense Home?】Babysense Home was developed for home use, leveraging the proven technology and track record of Babysense. This product continuously monitors the baby and alerts you with an alarm sound and warning lamp when there is a change in the baby's movement. 【Baby's Safety & Parents' Peace of Mind】Babysense Home has two sensor panels that are placed under the mattress, so it does not come into direct contact with the baby and can cover a wide area. Because it constantly senses the baby's movements, it provides peace of mind to fathers, mothers, and everyone who watches over the baby. 【Easy Operation】After installation, you can easily operate it by simply turning the power button ON/OFF. Operates on batteries, no power supply, internet, or app connection required. ---------------------------------------------