These are sold at Dollar Tree as 3 pack of Plastic Snack Containers with Lock-Top Lids. I haven't actually used them for that purpose though. I think they wouldn't be so great as a snack container because if you want to fill them up completely, when you open them up, it's possible that some of your snack will come spilling out of it, due to the way that the lid makes up about the top 1/3 of the container.
What I use them for, so far, are storage boxes, mostly for tiny electronic items, such as batteries, memory cards, and cables.
As you can see, they can fit quite a bit of stuff in them. I'd probably be able to fit in more memory cards if I took each card out of their individual cases, but since I don't actually have many more than that and they still fit inside, I kept them in their cases. In total, there are 10 memory cards/adapters of various sizes, two micro SD card readers, and one USB wifi adapter. The one in the middle has 10 AA and 2 AAA batteries, with room for a little bit more. The one on the right has a USB power bank, a USB car charger, 1 micro USB cable, and 2 lightning cables.
There were 3 packs of 3 at the time I bought these, but I only bought 2 of them since I didn't know how many I'd need or what they might be good for. I haven't seen them in the store since then, so maybe I should've bought them all because I have plenty more cables to store.
If you're actually looking for something that'd be good as a snack container, I'd probably get these instead because of their flip top lids. I've only seen them in store with Disney's Frozen characters on them and none of the plain ones. They're also only sold individually, so $1 each. If I could find the 2 packs of those in stores, I'd probably at least pick up one of them because they seem like they'd be perfect for snacking.