40 pieces/set 3dd color screw nut bolt-smart jigsaw puzzle game. 40 pieces/set 3DD Children's Color Screw Nut Bolt-Smart Jigsaw Puzzle? The xa0 features rich colors and smooth edges, so you dont have to worry about hurting your child. Small hand nuts and bolts can be easily combined. Use your fine motor muscles to tighten and loosen these large plastic nuts and bolts. Improve manual flexibility, hand-eye coordination, color recognition and matching shape sorting, increase concentration and attention. Specification: Type: Nut and Bolt Toy Material: Plastic Quantity: 40 Pieces Recommended Age: 3-7 Years Old Features: Educational Toys DIY Building Color Size Details Square Nut: 5.2cm X 4.2cm X 4.2cm/2.05 X 1.655 X about 1.65 triangle nut: 5.2cm X 4.5cm/2.05 X 1.77 (approximately) Hexagon nut: 5.2cm X 4.2cm X 4.2cm/2.05 X 1.65 X 1.65 (approximately) + nut: 5.