The Yellow Door Natural Focus Frames are a set of three wooden frames which nest inside each other. They can be used as a frame for transient art projects using materials collected during outdoor activities. They are also great for focussing attention on an area for close inspection such as bug counts. Set contains 3 sizes, internal dimensions:. 1 x 205 x 135mm. 1 x 150 x 80mm. 1 x 95 x 20mm. The Yellow Door Natural Focus Frames:. Helps children to make sense of their physical world. Develops creative and critical thinking skills. Complements a natural environment. Made from sustainably-sourced FSC approved beech wood. Age Suitability: 18 months +.