1000 Thread Count 6-Piece Sheet Set

76"x80" fitted king sheet? You will need some serious muscle to make this fit anything deeper than a 10" mattress.
78"x80" is the standard. American made sheets from the 20th century were actually 80" x 80".

King size mattresses are 76x80.

Definitely not high quality 1000 thread count sheets. Should have known better but took a chance anyway. sigh