Optex 12m Anti-Mask High Mount Outdoor Dual Technology Detector (S3628A)The HX 40 PIRs are mounted between 2. 5 and 3 meter high and provide a volumetric outdoor intrusion detection up to 12m. The HX 40 series is ideal to protect the approach of the building and has been designed to differentiate between human and small to medium sized animals reducing a lot the risk of false alarm. The HX 40DAM is the dual tech model, a combination of both PIR and Microwave sensors with active infrared anti masking.