How is the quality? Do you think it will last long?

That sucks, but good to know! I went back to get them shortly after this pic was posted, and they no longer had them in stock. Maybe thats why they stopped selling them? 
I have bought a lot of pencilcases there since then, especially the clear ones they have in the office supply isle, and those zippers have held up for me... but I guess these things are pretty hit or miss!

That purple Fanny pack is bad quality. I bought it in a few colours and the zipper has broken on every single one.

Spotted fanny packs/slings 👀