Bold SX-43 Bold Smart Cylinder. Start your keyless life with a Bluetooth-enabled smart lock that provides easy and reliable access control. Simple to install and operate via smartphone or PIN. Size: 43 mm (maximum inner dimension 45 mm, outer dimension 30 - 45 mm). Keyless: Conveniently operated via smartphone with the Bold app or PIN. Power supply: CR123A battery / battery life up to 2 years. Bluetooth: 2-factor authentication and additional end-to-end encryption. Suitable for almost any door, including emergency exits. Easily replace your existing lock. Range of up to 5 meters. Backup PIN: If you forget your smartphone or the battery is dead, you can enter a PIN programmed through the app into the lock. (Input is done by turning the door knob left and right). Access types: Permanent, temporary, weekly, and recurring. Receive push notifications from designated users. Locking via the app with or without internet. Locking by pressing the button on the inside knob without a smartphone is possible. For admin users: Access to the lock log. Automatic activation via the app can be set: Unlocks the lock without having to take the phone out of your pocket. Notification when the battery in the lock cylinder is low. Bold Connect: The lock can be controlled over the internet via the Bold Bridge (optional). Suitable only for Euro profile cylinders.