Tested and confirmed to be working. New batteries are included. This is a type that attaches to diapers. It alerts you with an alarm for situations like sleeping on the stomach or high temperatures. I purchased it on Amazon in 2024 and used it for about six months to a year, I think. The alarm often went off when the body temperature rose. I was worried about SIDS, so it was a great help to know the temperature. It also accurately detected the position of the baby, whether they were on their back, side, or rolling over. I will pack it with bubble wrap for shipping. I may suddenly delete this listing due to moving... Please forgive me.