This 2.75" ID Wall Eye Wall Port was designed to work in conjunction with the line sets associated with most mini split units. This unit ranges from 4.5" - 7" in thickness and comes with a 1/2" flange that sets nicely on the wall. This is the unit we would recommend for most 2 x 4 wall applications. Just drill a 3 3/8" hole in your wall and screw this unit into place to have a neatly dressed, 2.75" tube from one side of the wall to the other.