 This is the most popular item in the back rooms by far. It's also the most useful. It's object number 87 or the worn sack. It's a pretty funny name to be honest. But to make the object, you actually have to craft it yourself and you're gonna need a few things. First, you need to get a debris holder out of a mobile vacuum cleaner entity, which is pretty much an anomalous vacuum cleaner that's found in back rooms levels. You take off the sack on the back, then you also need to find an old worn out backpack. And somehow you have to insert that vacuum's waste bag into the worn out backpack and it makes the backpack have almost infinite storage capabilities. The process isn't very well known, but apparently it creates a massive storage system that's in the size of a small backpack. Kind of like a shulker box for Minecraft. Let me know in the comments if you would make one of these things to carry stuff with you.