Outside is constructed of 16-gauge steel. Soft foam on the inside protects valuables. High-Strength lock mechanism performs reliably, time after time. FOOLPROOF SECURITY- Precise fittings are virtually impossible to pry open with hand tools. Built-in computer blocks access after repeated invalid keypad entries. Tamper indicator alerts you to invalid entry attempts. Motion detector with audio alarm helps guard against direct tampering (Multi Deluxe model). Audio low battery warning helps guard against unexpected power loss (Multi Deluxe model). CUSTOMIZABLE CONVENIENCE- Battery power provides maximum security and easy portablility. Optional high-strength security cable secures GunVault in home, car, RV, office or motel. Mounts almost anywhere, in any direction. "Learn buttons" make it easy to program over 12 million user-selectable access codes. Interior courtesy light makes for more convenient access (Multi Deluxe model). Power connection jack for external AC or DC power supply (Multi Deluxe model). ADVANCED ACCESS- conveniently located keypad is easy to use. Unique No-Eyes® Keypad allows for quick access. Audio feedback confirms each correct keypad entry. Audio disable option adds the security of operating in silent mode.