My other safe, newer and much heavier, has separate mechanical and e-lock mechanisms. The e-lock has dual batteries and an 8-digit combination.

Both safes are bolted into my slab.

A safe gotcha to watch out for is the actual interior space, i.e., area available AND still be able to close the door. Over time needs change. My newer safe has such a thick door (impinges so far into the interior) that I will need to totally reconfigure it to fit my “other items” when I sell my old safe (downsizing) and transfer its contents. So, if you foresee putting large objects in your safe (e.g., a storage box of “stuff”), take the empty box when you go safe shopping… and consider typical box-access scenarios (and frequency).

Final note…think very hard on all the costs and the difficulty to move the safe to where it will be located. Getting the safe dropped off at the end of your driveway, or into your garage with straight-in access, may be all the seller offers. Which can be a very long way from getting it where you want/need it located. Consider the need to temporarily remove doors (then wide enough?) and whether your floors, from entry to final location, can support the load (safe AND moving gear). If you have crawl space along the way, or want the safe on a second floor, have the discussion with the seller BEFORE you sign the deal. The “moving cost” may exceed the cost of the safe. And… the difficulty getting it located to where you want it, may, quite literally, become financially or practically impossible.