Directions are like IKEA so have patience. All the parts seem so flimsy and you’re wondering, really? Really! Once all put together, these are not going to fall apart or fail you. The first one took me an hour and that includes figuring out the spacing I wanted between shelves for what I intended to use it for (a garden shed) the next consecutive units took about 25 minutes each. It’s a bit tedious to figure it out and get going but take your time and don’t get frustrated. I do recommend using a regular hammer to tap down the shelves gently, making sure to tap on the outside corner so you don’t bend down the insides of shelf brackets. They say to use a rubber mallet in the corner but you can’t get that to tap right in the corners. One thing to watch as you tap down, is that the tabs go in on the inside, and I pushed in with my finger to ensure they went inside instead of outside. Although they seem a bit tight to tap into place, they are very easy to tap back up and out again, as I ended up moving some shelves after all put together. You definitely need to attach to the wall for stability. It isn’t clearly stated they they should be, but they do mention to use screws or anchors etc. I’m very happy and would purchase again!