Our 16" x 8" x 4" 200#/ECT-32 Flat shipping boxes feature a durable, corrugated construction that protects and conceals shipments to help ensure safe arrival. 16" x 8" x 4" Corrugated Flat Boxes meet requirements for 200#/ECT-32 kraft C-flute single wall corrugate. Great for packaging books, frames, electronic equipment or medium-sized items.