We received these chairs (2) & the angle of the bases were cut wrong.  The chairs rested on corners instead of a flat surface.  Wayfair shipped 2 more chairs & they were fine.  Assembly is easy needing only a wrench & screwdriver.  The chairs that these replaced had a contoured seat & were more comfortable to sit in.  Also, these chairs are real heavy, which isn't necessarily a bad thing (especially if you live in an area with high wind gusts).  They feel substantial but I wish were more comfortable.