The plastic black parts that go in the drawer to connect the wood all together the kind of look like little triangles I was sent three broken ones and I found that finding out what piece of wood was what cuz they didn't all have stickers on them and some of them didn't have the letter stamped on the side like others did also just found it kind of hard to get everything together also seems pretty flimsy before it set up but once you put it where you need it to go it works pretty good it's a little bit smaller than I thought it would be but I still like it