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 mirrors Set includes 10 blocks Ideal for indoor/outdoor STEM activities Smooth rounded corners and edges Standard unit block measurements Material: Rubberwood block frames with inset double-faced Mylar windows Educational Focus: Science, visual perception, block play, size relationships Suggested Age: 2+