Free-Style HandleSwing the handle up to turn the privacy deadbolt to double lockpush the handle down to open the door pls noted this can be locked automatically after you close the door4 Batteries=365 DaysPowered by 4pcs AAA 1.5V batteries ,which can be lasted for about 1 year.batteries is located at the front panel ,so you can easily change the batteries from outside door .product Structure1、Hidden Mechanical Key Holeemergency key to open the door if you do not want yo use fingerprint or the battery is dead.2、Batteries Is Located At the Front Panel so you can change the batteries from outside door 3、Zinc Alloy Handle &Stainless Steel Panel color will not fade in 10 years,anti-corrosion4、One Touch AccessFingerprint scanner will wake automatically once you place your finger on it and is conveniently positioned to accompany your natural hand position. One seamless action allows you to wake the lock, read your fingerprint, and unlock your door. The whole unlock action takes only 1 second. It can auto relock your door for you so your home is always safe.Panel SizePlease see below drawing Here are two types of moretise When you place your order ,pls let us know which one do you needBuying GuideHow to determine whether the lock fits your door or not?(1)Measure door't thickness;(2)Measure the length of guide plate;(3)Measure the width of the guide plate.If you are not sure whether it can be replace your old lock or not,please contact and tell us the details of it directly!