After about 1.5 years of occasional in home use, by someone significantly less than the 400 pound capacity, the steel (?) plate on the bottom of the chair mechanism) fractured and the chair separated from the base, resulting in falling backwards onto the floor after leaning back. Column and part of plate actually ripped out of the steel plate.  Not he heavy duty chair it is advertised to be which is probably the reason for the warranty only being 90 days.