Grimm's wooden concentric circles and rings

Large creative puzzle to be played on the floor.
In combination with other building blocks one can build modern Architecture and create new fantasy worlds over and over again.
The Concentric Circles and Rings are a perfect complement to GRIMM´s World of Numbers (42100 Stepped Counting Blocks, 60310 Building Set Numbers, 10234 Colourful Bead Stairs, 03070 Figures for counting and story telling).
This product is recommended by "spiel gut" (good toy guide).
20 pieces.
Materials: birch ply wood, non-toxic water based color stain.
Size: diameter 2-20cm.