At these two corners they must be double from the bottom all the way to the top and fitted into a single ring; both shall be like that.
NIV
They shall be coupled down below and coupled together on top with one ring. Thus shall it be for both of them; they shall form the two corners.
AMP
And they shall be coupled together beneath, and they shall be coupled together above the head of it unto one ring: thus shall it be for them both; they shall be for the two corners.
KJV