Montessori Wooden Nuts and Screw Bolts Toy - Montessori Practical Life Materials for Toddlers. This is a wooden rectangular shaped base with 7 different diameter holes in it. Adding seven different diameter metal bolts and matching nut. Children can screw the suitable bolt into the suitable hole and screw the suitable nut to fix them to the wood. This activity can develop Children' attention, judgment, and practical ability. Also improves kids hand-eye coordination. Kids will also learn the difference between diameter. Best for Montessori classroom, home schools, etc. Age Group - 4 Years to 10 Years Dimensions - Length - 11.5 inch Height - 2.75 inch Width - 3 inch Items include - Wooden Base with 7 Nuts and bolts. Warning - Small Parts - parental supervision required. Not for kids under 3 years. Note: Please understand slightly color difference due to different monitor; please allow 2-3cm size difference due to manual measurements.