The Set of 10 Guidecraft Mirror Blocks features hardwood frames with soft, rounded corners and Mylar mirrored double faced interiors.The Guidecraft Mirror Blocks have smooth rounded corners and edges making for safe play for children 2 plus.The Guidecraft Mirror Blocks are great for indoor and outdoor STEM activities and have an educational focus and can help children develop core skills such as Visual perception,sizes and relationships and block play. Hardwood block set with mirrorsSet includes 10 blocksIdeal for indoor/outdoor STEM activitiesSmooth rounded corners and edgesStandard unit block measurementsMaterial: Rubberwood block frames with inset double-faced Mylar windowsEducational Focus: Science, visual perception, block play, size relationshipsSuggested Age: 2+