4" Expansion Box Slab Die Kit for 4" Extruders.  Cast aluminum expansion box die kit for slabs.  It will produce a 6" diameter round tube with a wall thickness of 3/8" or 1/2". To layout an 18" slab, cut tube down one side of the tube.  Use of this Die Kit requires the 4" Aluminum Expansion Box.  Made in the U.S.A.