If you've ever locked your keys inside your house, or just had to bring along extra keys when they weren't necessary, the Biocav Fingerprint Recognition Deadbolt is the perfect solution for you. This deadbolt uses biometric technology to keep your home safe and secure. The fingerprint door lock uses 4 AA 1.5V alkaline batteries which are included. The fingerprint door lock uses biometrics in order to identify and authorize registered fingerprints. With a maximum of 50 fingerprints, this Biocav Fingerprint Recognition Deadbolt system is excellent for the home or office. Restrict access to different areas of your business or have peace of mind knowing guests or service providers aren't cutting copies of your key. Open by Password The Fingerprint Recognition Deadbolt can be opened by fingerprint or PIN making it more convenient for users. If a family member has not yet registered their fingerprint you can give them a PIN between 3 and 10 digits so they won't be locked out. Convenient Operation and Durable The fingerprint door lock system can be operated with one touch. When opening the deadbolt from the inside you can either manually open the lock or just push the blue "open" button. A red "lock" button quickly extends the deadbolt and locks the door. There are 12 keys (0-9, #, *) on the outside, which are built to withstand external shock. Simple Operation For such a complicated and technologically advanced product, programming is surprisingly simple. When programming the unit, all functions are associated with a sound that makes it easy for a user to operate. Built-in Security If the door is opened abnormally or the unit senses the door being forced open the system will automatically sound a built-in alarm. If an incorrect code is entered the system will automatically cut off power for 30 seconds to prevent multiple password attempts. Low Battery Warning When the unit beeps, it's telling you that the battery is 80% drained and it is time to replace the battery. If the battery does run out, all password and fingerprint data is safe and will not be erased, eliminating the headaches of inputting the data again. Also, if the battery runs out before being replaced, the user can still open the door using the emergency battery terminal (simply align terminals of standard 9 volt battery with unit's emergency battery terminals to provide temporary operational power to unit). Note: Unit should be installed in a location protected from precipitation.