Than I was trying to install this in my shed, I drilled pilot holes and tried to use the screws included in the kit. The head of the first screw snapped off immediately and the remaining screws stuck in the wall. I tried another one and the same thing happened. To solve this I drilled 2 new pilot holes in the plastic on top as you can see in the picture and so fixed it with better quality screws I bought elsewhere. Seems to me that these shelves are designed more for drywall and slowly screwed together by hand. I would consider returning both clips/holders immediately but other than that they work pretty well and have been holding shovels, snow shovels and brooms for over a month now. If you are considering this product, get an extra 1 1/4" wood screws just in case :)