Thanks for adding that coupon to the site, flylow.
External dimensions at the largest points are 7" tall x 5" wide (at the lid) x 11" long (includes hinge and latch). Internal dimensions at the smallest points are 6" deep 4" wide x 9.5" long. I have three of them for 9mm, and I easily fit 600 rounds of ammo (12 boxes of 50 rounds each) in each one. Could likely fit even more, if I emptied the boxes and dumped them right into the ammo box.
I have one for 22LR, and it's less than half full at 1250 rounds. I have another one for .40, but I've only got about 200 rounds of that ammo, and it's less than 25% full. I only have one gun that uses that ammo and I don't shoot it near as much as my three 9mm guns.
Now that I bought several more this evening, I also use them for lots of small, miscellaneous related equipment. The decal as seen in the coupon above, is not on these boxes, but there is a small rectangle decal, that easily peels off. These are all grey, with a black latch. Great deal at $3.99, small enough to be convenient and easy to carry, even when full. I'll probably go back and buy a few more, just to have for spares. These are almost identical to all the ones I've seen in gun shops, and they range in price from about $6 to as much as $13. I used the above code and bought four of them this evening at Harbor Freight, and the total was $17.16 after tax.