The Sensory Blocks are made of natural wood and have several brightly colored windows. The different textures help develop children's dexterity as they learn to distinguish between the different sensations through touch and feel. Look at the different sizes, shapes and colors; feel the grooves and different colored windows. Great for developing hand-eye coordination, build and stack any shape and let the light flood in for a beautiful lighting effect! These sensory toys work best when placed near a window. These sensory baby toys are made from responsible, high-quality materials and meet current European safety standards. The smooth edges do not cause cuts or splinters. These wooden shapes have transparent cores so that your little one can discover light and sound in a playful way. Ideal for sensory development and sensory play.