This is a Woodcraft Construction Kit of a Submarine. There are 29 interlocking 3mm wooden plywood pieces and when assembled measure 13 1/2" L x 4" W x 6 H. These high grade 3mm wood puzzles come individually shrink-wrapped w/instructions & sandpaper included. Pop out the pieces and go! Painted or left as natural wood, it"s a challenging, educational and creative activity for all ages. Start your collection today! The units are made of 3mm plywood and the pieces are individually slotted to interlock with one another to form a 3D model. Everything is pre-cut and assembled by pushing the pieces together. There is nothing to cut or glue. The 3D Puzzles are even paintable if desired.