【Development Set】This second generation magnetic blocks development set 102 pieces, include 32* Square, 32* Triangle, 4*Isosceles Triangle, 2*Hexagon, 6*Semi-Circle,2*Wheel, 24*Castle Plastic Card, 1*Storage Case or 1*Colorful Cardboard Box randomly, 1* Color manual with many reference models, 1*Warranty card. 【Safe and Durable】Made of food grade ABS plastic, safe magnet, stainless steel plate.The magnet is wrapped in stainless house,which locked in plastic cover, ultrasonic welding process to tight the cover, double protection,ensure the magnet won't easily fall out, durable for long-term use. 【Strong Magnetism】 The super magnets are encapsulated within the stainless steel pieces, equate the magnets contact directly,thus making the magnetic tiles with much stronger magnetism and the models are stronger and more stable. 【Learning While Playing】 Kids will spend hours keeping play this magnetic toys.Good to develop kid's color and shape recognition, creativity and imagination, practical and design ability. Perfect for STEM preschool educational games.