This combination of wood and metal provides the puzzle a unique appearance and different level of complexity. The wood is natural and the different colors of the pieces are because different kinds of wood are used, which makes it very special to have as part of your collection.
This is a unique packing problem, where there are 2 rulers laying in 2 layers on a wooden frame. The rulers are broken to different segments where the smallest segment is 1 and the longest is 7. The segments on each ruler are connected with a metal pin that allows you to turn them to many directions and this makes the puzzle pretty difficult.
The objective is to take both rulers out of the frame, make each one of them 1 straight ruler, and then fold and put them back together to fit inside the frame in a way where they make a 7x6 rectangle and they lay in no more than 2 layers.