This is a nice unit, but the instructions could use some clarification or a little more detail.   Installing the sliding rails was a bit of a problem because one hold is round and one is oval which means it may not align perfectly.   Maybe that is intentional for adjustment but seems unnecessary if the holes are precision drilled.  I tried to eyeball it, but must has missed because the top two drawers are very hard to open now and stick so much that I guess I need to remove them and try adjusting the mounts inside (without taking it apart, hopefully).  The bottom file drawer is nice and smooth, so I will be very upset if I cannot get the top drawers smoothed out too.