63 PIECES - The more the merrier! Our STEM building educational toy set has enough blocks, wrenches, moveable wheels, nuts, and bolts for up to 4 / 6 kids at one time. LEARN & PLAY - Let your kid's creativity and imagination run wild! These STEM building toys are ideal for a 4 to 8 year olds, but provide educational fun for all ages. BOOK OF IDEAS - Spark the creative genius in your child with 42 designs for beginner, intermediate, and advanced builders in our tinker toys guide. SAFE TO USE - These bright, colorful, non-toxic building blocks for kids ages 4-8 are certified Phthalate, Lead, Cadmium, and BPA-free.