Wow - blocks you can actually fill and refill! Our exclusive set takes block play to a whole new sensory and creative level. Look at what's inside, sort, shake, build away. Perfect for housing beads, shells and many other small objects. Contains small parts. Filling requires adult supervision. Crafted of sturdy birch wood and acrylic*Ideal for nature/science studies* Perfect for teaching sorting, counting or patterning* Playing with blocks builds fine motor skills and enhances eye-hand coordination* Helps children develop concepts of spatial relationships* includes:*4 square blocks: 4"H x 4"W x 1-3/4"D*4 rectangular blocks: 4"H x 8"W x 1-3/4"D*4 triangular blocks: 5-1/2"H x 10-3/4"W x 1-3/4"D