Kevo2, 2nd Generation, Brass, Bluetooth Electronic Deadbolt, Uses The Latest Bluetooth Technology, Use A Compatible Smartphone Or Included Fob As A Key, Functionality Is Similar To Current Automotive Passive Keyless Entry Systems Which Allow The User To Unlock The Door Without Needing To Take A Key Out, Kevo Is Easy To Install, Program & Use & Operates On 4 "AA" Batteries.