Yale YRD446BL-619 Satin Nickel US15 Assure Lock With Bluetooth Technology, designed as keyless lock that uses a smartphone key or a 4-8 digit pin code. Compatible with Android devices running 4.3 or later iOS devices running 9.0 or later, and Samsung Gear smartwatches running 4.3 or later. Forget carrying your keys, lock and unlock your home using your smartphone, and you can share digital keys with friends and family, you can view access history and costomize lock settings and pin access codes, all from the Yale assure app. Yales Assure Lock With Bluetooth can be upgraded using the Yale Network Module to seamlessly integrate into most home automation and alarm systems. This lock is ANSI/BHMA A156.36, Grade 2 certified, it replaces existing deadbolts with just a screwdriver, it fits on doors 1-3/8" to 2-1/4", the face bore hole is 1", and it has an adjustable back latch. For people that don't have a phone this lock has a 4 to 8 digit pin code, and the lock can store up to 12 diferent pin codes that can all be created or deleted using the Yale Assure App. This lock uses 4 "AA" batteries, and it will worn you when your battery is running low. If the battery dies, touch a 9V battery to the battery terminals at the bottom of the keypad and enter your pin code.