The Master Lock No. 5440ENT Bluetooth Portable Lock Box features a 3-1/4" (83mm) wide metal body for durability and a fully removable shackle for convenience. The Master Lock Vault Enterprise system is designed to support Many Locks and Many Users with unmatched security, simplicity and accountability. Administrators control individual or system-wide lock access with our convenient web interface, while users enjoy simple, secure access to assigned locks or lock boxes. Product Features • Same as EC units • Includes Master Lock Vault Enterprise IOS and Android app, and web interface, designed for business applications working with many locks and many users. • Use your smartphone to open and manage your lock with the Master Lock Vault Enterprise app • No keys to lose, no combinations to forget. No unauthorized key duplication. • Backup access using numeric code on lock keypad • Share access with others - temporary or permanent • Easily monitor access with robust data and audit trails • Removable shackle for easy portability and installation. • Low battery notification & reminder on device and in app • Comes with easy to replace CR123A battery • Large storage capacity for keys and access cards.