Review on Ultimate Stackable Lab & Scientific Products for School Lockers - Adjustable Tools for Science Enthusiasts by Brent Henderson

This shelf is very easy to assemble. However, the mechanism to increase or decrease the width is just a button under the shelf. It clicks as it extends, so when the shelf is pulled out to the width of the locker (it's wide enough), but since it's gradually increasing I can't extend it to the next step so the shelf is held securely in the locker. It's very wobbly and every time you put something on or take it off it moves and walks away. Not a very good buy, I recommend looking for something else.