1、Quality Chip: Motion sensor doorbell uses a high grade chip, HiFi speakers, and can be independently customized for exclusive voice. 2、Infrared Sensing: Entergy doorbell adopts mature human infrared sensing technology, which can work stably and normally even in dark environment. 3、2 Modes: Wireless motion sensor alarm can freely choose single song or full song loop, and 8 levels of volume adjustment to meet your various needs. 4、Safe and Reliable: The PIR motion sensor alarm is made of ABS housing, which is flame retardant and anti aging to prevent and reduce safety hazards. 5、Multipurpose: Wireless sensor doorbell is used in bank self service area, warehouse heavy duty voice prompter, corporate employee attendance prompter, engineering safety voice prompter. Item Type: Motion Sensor Doorbell Material: ABS Size: Approx. 8.9 x 8.7 x 4.4cm/3.5 x 3.4 x 1.7in Sensing Mode: Human Infrared Induction Detection Angle: Left and Right 120 Degree, Up and Down Angle 60 Degree Volume: 8 Levels of Volume Adjustable Storage Capacity: 4MByte Volume Size: ≤100dB Gross Weight: Approx. 196g/6.9oz Uses: Bank Self Service Area, Warehouse Heavy Voice Prompter, Corporate Staff Attendance Prompter, Engineering Safety Voice Prompter 1 x Motion Sensor Doorbell 1 x Plastic Box 2 x Flat Head Screws 1 x Self Tapping Screws 2 x Plastic Sleeves 1 x Instructions