Top critical review
One Star for size lie, 20L instead of 40L
Reviewed in the United States on July 25, 2018
tl;dr: this backpack is 20L to maximum 25L.
Just look at the picture of the backpack next to 6 of 1-gallon (4L) jugs. The backpack is supposed to contain 10 of these jugs. No way, no how. But let's get mathematical on this b.
Stated in the description measurements are: 22.8” x 13.4” x 7.9”
Let's assume height is correct and concentrate on length and width. Half of the perimeter as stated should be: 13.4 + 7.9 = 21.3”
Instead, top measures 16” and bottom measures 17”. Fine, let's use larger bottom measure. So perimeter/2 is: 17” or 80% of 21.3”
To calculate actual length and width as 80% of stated: 13.4 x 0.8 = 10.7; 7.9 x 0.8 = 6.3
And so actual volume is: 22.8 x 10.7 x 6.3 = 1537 cubic inches or 25.2 Liters (6.7 gallons). And that's assuming the height was really 22.8” which I really doubt and ignoring it measures smaller at the top. But wait, there are 2 expandable mesh pockets on the sides! To me they look to be able to hold 1L each max. Nah, let's go crazy and stick 2L soda bottles in each pocket. They won't fit, will stick out and fall out, but hey, I'm just crazy like that. So, 25+2+2=29L. I spit on that number and add 1L more because reasons! So now it's 30L. NO.WAY.THIS.BACKPACK.IS.40L.
My guess is that if this backpack measured the way the description shows, then it would be 40L. But it doesn't and isn't...
edit: Adding picture from G4Free representative showing how they measure height of the backpack. See how they had to over-stuff it so it would match description size? How the backpack profusely bulges on the bottom left and less on the bottom right? Ridiculous! As I suspected, the stated height is incorrect too, it is about 18" instead of 22.8"; so the backpack is actually about 20L (18"x10.7"x6.3") :tide
edit2: Was asked via email to delete my review for a reward of $23 amazon gift card. I proposed they send me instead improved and true 40L backpack for a re-review. They weren't interested and insisted on me just deleting this review for $23 reward. Such wholesome and honest seller, a beacon of moral integrity and ethical way of conducting business! :2tide