The 4in Height Adjuster panels can be used in any part of the wall assembly to gain an additional 4" in height. The height adjusters have 6 vertical webs spaced 8" for continuous fastening. The webs have the same locking web teeth that secure the panels to any of the other Stronghold blocks. FD center webs can be installed onto the panels on both sides of the wall to essentially make a 4" height structural block. Height adjusters are often used in window sills to increase the wall height under a window opening without having to cut full height blocks. The foam panels are 1.5lb in density and 2.75" thick providing consistent R-value in the wall.