The bottom shelf is so low that when you are mounting it, the hardware has to go into the baseboard molding. We do not want to do that and so are still trying to figure out how to mount these without damaging that wood. The dimensions note the difference in height of that bottom shelf but the implication of that is not clear and would be helpful to have explained as well. Happy with the shelving but not quite happy with this aspect. If they aren’t mounted, not sure that we will be able to use them.