Description: This door alarm can alrm immediately when door or window is opened by others, in order to detect burglar or thief. It also can program with remote control and detector function. Under the arming condition, when magnet is seperated from contect, model Kr-D2 can be alarming directly to prevent the inturder from doors and windows. The wireless door sensor alarm host connects with PIR detector, door sensor and emmergency button, etc. Perfect for your home, office, garage, dorm room, factory, financial office, store, etc. Note: requires 2 x 3A 1.5V cell batteries (not included) Specification: Material: Plastic Product Size: Approx. 7x5x8.5cm/2.76x1.97x3.35 inch Battery: 2 x 3A 1.5V cell batteries (not included) Package Includes: 1 Piece Door Alarm 1 Piece Contact 1 Piece Magnet 1 Piece English Manual Note: Since the size above is measured by hand, the size of the actual item you received could be slightly different from the size above. Meanwhile, please be reminded that due to lighting effects, monitor brightness, contrast settings etc, there could be some slight differences in the color of the pictures and the actual item.