The product works fine but it needs clarification, for the business I am planning to open, it doesn't work. The sensor's direction detects everything, even walls. It can only be installed behind the door if you are willing to open and close it all the time or as the customer enters, on the right or left side of the wall (I have shelves there) without anything interfering. It can also be installed on the ceiling if the space has relatively low ceilings. For household use, maybe if there is a child in another room and there is no visual contact. This malfunction to fit in a specific space removes one star.