Fangrui Product Details [sturdy And Durable Metal Texture] Our Timer Lock Box Is Made Of Sturdy And High-quality Metal Material, Ensuring Long-lasting Durability And Providing A Secure Storage Solution For Your Items. Once The Box Is Locked, It Cannot Be Overwritten. [powered By Battery Or Usb Connection] Many Customers Complained That They Could Not Unlock The Phone Lock Box If The Battery Ran Out. Our Phone Locker Has Solved This Problem. Its Powered By 4 Aa Batteries (not Included), And We Also Provide An External Type-c Port In Case The Battery Dies. So Even If The Battery Dies During Locking, The Timed-release Lock Box Can Still Be Unlocked Via External Usb-c Power In An . [audio Alerts And Extendable Lock Time] The Timed Locker Will Beep 7 Times When The Lock Is About To Be Activated, And 1 Beep When The Lock Time Is Over, Which Can Serve As A Useful Reminder Of The Lock Box Status. You Can Also Turn Off Audio Prompts If Desired. This Mobile Jail Allows You To Increase The Time Remaining Before Unlocking. The Max