... distinguishthe different signal between intruder and petSpecifications:1.Model: DT-7225 DT-7235 DT-72452.Detection method:dual passive infrared and microwavecompound technology3 ... interference:> 20V / M (20MHz ~1000MHz)10.Dimensions: 119X71X42mm Alarm Detector (DT-7225, DT-7235, DT-7245)