DW Expandable EF Series Frames are
designed to accommodate the broadest range of wall construction
with a single adjustable product. Users of this product claim the
EF Series design is the best of its kind on the market today. By
selecting EF1, EF2 or EF3, EF Series frames can be used in wall
thicknesses ranging from 3 1/2" to 12". These easy to install
frames are manufactured of 16 gage A40 galvanneal steel and can be
fire rated for up to 90 minutes.
