Exodus 39:4
From this they made two shoulder straps for the ephod and attached them to its sides, so that it could be fastened.
Treasury of Scripture Knowledge
Summary
They made shoulderpieces for it, to couple it together: by the two edges was it coupled together.
General references
Bible References
General references
Exodus 28:7
It should have two shoulder straps attached at the top corners so it can be fastened.