Another reviewer described this as keeping honest people honest. That's the correct assessment. Wall thickness is around 1/16". A good grinder would have this safe opened in a minute or two.
That problem aside, this will do the job for which I intended it. My small business uses a set of Network Attached Storage (NAS) drives for frequent data backup. They fit nicely in the safe and the rear access holes allow power and Ethernet connections to pass into the safe. That makes this solution functionally similar to using equipment lock-down cables, but is substantially better in delivering physical security for the assets.
The internal shelf is removable, but it's height within the safe is not adjustable. However, the mounting brackets for the shelf provide a substantial enough platform to kludge-in a height adjustment solution of your own.
I did have a small problem with the size of the rear holes. They are not of a large enough diameter to allow a full size 3 prong power plug to pass. (As a design enhancement to Sentry, I'd say keep one of the holes circular and make the other one square.) I could have chosen to not use a grounded power option for the equipment I was protecting, or I could have razor-bladed off plastic from the power plug I was using. I chose instead to make one of the pass-through holes a little larger. I'll warn that if this is a choice for you, be prepared with a substantial diameter drill bit.
The bolt-down hardware that is supplied with the safe is pretty unsubstantial, and, with the thickness of the wall, the bolt heads could easily be persuaded out the bottom of the safe. I bought and installed far larger lag bolts and concrete anchors and bulked-up the internal bottom of the safe with some extra steel plating. Here again, I'd say there are some simple design features that Sentry could add with very low cost.
Before making this purchase, I did consider a number of other alternatives. From a price/performance perspective this one is really hard to beat. Sentry does make a safe that passes a USB connection into its interior. If that model were available with power and Ethernet, I'd have gone in that direction instead of this one. NAS seems to me to be the future direction for SOHO users. I suspect Sentry will catch on to that at some point.
I don't think I'd keep anything with great market value in this safe. However, my business data has extremely high value to my business, so this fits the need well. Nobody in their right mind should go to the trouble of trying to get at a couple hundred dollars worth of hard drives with this thing in their way.
This solution could also find a use in a home. If you have service people who are allowed entrance while you're away, this would provide the right level of security and deterrence -- again keeping honest people honest. Also, if you've invested hours (days? weeks?) of your time ripping your CD and/or DVD collections you'll find yourself in exactly my position: you really don't want to loose your drives, but you also want them on and accessible.
Customer reviews for SentrySafe - Security Safe - 1.2 Cubic Feet for