That looks like an identical baby brother to my safe. Mine is an AmSec, but rebadged as something else, I forgot off-hand, but it is AmSec, since only a limited number of companies make TL safes.
If I was forced to guess, I would say its 1800-2000 lbs. The one thing that is different than mine, the dial/keypad on mine is located above the handle, not all the way to the right.
Mine has a glass relocker over the sensitive bits. My bumpers are nowhere near that big, so I can't say what it is, and as already answered, the top left is a contact switch meant to be hooked to an alarm. My safe box in the top is welded in, it's 1/4" steel, so not easy to remove. I would guess yours is also welded in.
If you can get it cheap, go for it. Awesome safe, even if you just put some of you're higher end handguns/valuables in it, it's worth it. It's a huge peace of mind knowing when you leave for the day, everything in there will be there when you get back.
ETA: If you are looking dimension size, don't forget to add the hinges in there, mines are 3.5" added to depth, those look the same.