Outdoor/Indoor intrusion detector with curtain field-of-view PIR sensor + Microwave sensor + Anti-masking + Waterproof. CURTAIN creates a super narrow protective screen of 3º (like a curtain) to secure openings and open fields against intruders. This type of protection allows free movement of people within the protected site- without setting off an alarm. CURTAIN is waterproof and can be installed outdoors or indoors.