But postal abuse isn't the box or the vendor's fault, and the damage is mostly cosmetic.
Anyway, in case that link stops working, here's a photo:
I didn't see an obvious way to get it apart, even with the lid open. I could lift the aluminium cover off a little, so that might be part of the trick. There could also be screws under the display. (The display takes up a lot more of the screen than the Chinese padlocks do, so I don't think the trick to getting it open is the same.)
It has a MicroUSB hole in the bottom for charging, and three buttons: SET, + & -.
To set it up, you press and hold the SET button, and use the + & - buttons to set each setting, pressing the SET button again to move on to the next setting. The settings are Mode, Minutes, Hours. When you press SET after setting the hours, the operation is set.
The mode setting selects if it's in auto-cycle mode (mode 1, the default) or single lock mode (mode 2). In single lock mode, the box will lock for the specified time, then unlock when the time is up - and that's it. In auto-cycle mode, the box can be opened after the time is up, but will re-lock for the same period of time if it is closed again - obviously the intent is to, say, allow a cigarette or whatever every so often.
The minutes and hours settings are self-explanatory. The hours setting goes up to 999 hours 59 minutes, or just shy of 41 days, 16 hours. +/- increments / decrements the hour or minute, wrapping around as expected.
When you enter Set mode, the mode defaults to 1 and hours and minutes to zero. The only time it re-uses existing settings is when re-locking in Mode 1 (by re-closing the lid) without changing the settings.
When you close the lid, there is a five second countdown before the latch slides over to lock it; if you open it again before it reaches zero, it cancels the countdown. The lid also has magnets to hold it closed - the magnets are on both the lid and the body so I assume that the lid magnets also activate a reed switch - there's no sign of a mechanical switch. The latch is held positively closed - you can hear the motor running to open and close it. It's not a spring latch that could be shimmed or tapped. The latch engages a slot in the lid, so the lid can't be lifted over it.
There's not much metal in the latch, so if you really did need to get into it, I don't think it would resist much violence.
If the lid was closed while you were setting the time, you can open it to put things in before closing it to start the countdown. Only the act of closing the lid starts the timer.
I couldn't find any obvious non-destructive way to get into it when locked. I did try holding down combinations of buttons to see if there was an undocumented "emergency open" feature. I didn't find one.
I "locked" the box with the lid open (by holding it close enough to closed that it thought it was) and then held the latch while it opened. After it opened, the latch was loose, so could have been unlocked - I tried again with the lid actually locked and tensioned the lid while it opened - and it opened fine. so I think it's safe(ish) against accidentally keeping it locked after it attempts to open.
I'm reasonably impressed. I'd say the security level is pretty low - it's very much reliant on not wanting to break your toy. It is small and portable, but large enough that one could be confident of putting several keys in without needing to take them off their keyrings. I think you'd need to break it to open it, and I don't think you could do so undetectable (at least as long as the "detective" was paying attention). There might be a reset hole/button hidden under the screen like there is for the Chinese timer padlocks, but I haven't attempted to open it - there's no sign of a reset hole anywhere visible.
I kinda wish it defaulted to one-shot mode rather than recurring mode, but that's a minor niggle.
The display only counts minutes and hours, so you can't watch it count down. The display goes blank when it locks; it can be woken up by pressing a button or shaking it. I think that just bumps the reed switch that detects lid closure - it's not a tilt switch; rotating it without jarring it doesn't wake it up, but it doesn't need much of a tap or bump to get its attention. It blanks again after five seconds or so.
Once you set it, the display doesn't show the time again until after you lock it. So you could have a partner set a time, wait five seconds for the screen to blank, and hand the box to you to put keys et c in without knowing how long the lock-up will be - only once it's safely locked will you know how long your "sentence" is....
Below is the instruction leaflet that came with it:
