Smart safe connects to the Yale Home app, allowing the user to unlock and lock, share codes or remotely monitor every entry, to see who has accessed the safe. Can also be operated entirely hands-free using voice assistants such as Google Assistant, HomeKit and Amazon Alexa, or using a PIN code or key. Supplied with 1 override key. Works with - Amazon Alexa - Google Home - iOS App - Android App PIN Code Opening 3-8 Digit Code Length & 1 Key Supplied 20mm Width Locking Bolt Tamper Alert Freestanding or Wall-Mountable Key Override Hub Not Required Works with - Amazon Alexa - Google Home - iOS App - Android App PIN Code Opening 3-8 Digit Code Length & 1 Key Supplied 20mm Width Locking Bolt Tamper Alert Freestanding or Wall-Mountable Key Override Hub Not Required