Magna-Tiles are 3-D Magnetic Building Tiles by Valtech since 1997

Each tile has magnets along it's edges. The secret is the unique ability to attract even when the tiles are flipped. 
They always connect! 

Sized just right and easy to use, Magna-Tects develop fine motor skills as they start by stacking, making flat patterns, and 3-D Shapes, and with time, create complex Magna-Tiles Creations.

Magna-Tiles Clear Colors are translucent and colorful, like stained glass!

Magna-Tiles Clear Colors 32 Piece Set is the perfect starter set for any young Magna-Tect (Magna-Tiles Architect)

• The original 3D magnetic building sets that engage young minds by fusing together math, science and creativity.
• 32 translucent, colorful shapes including squares (2 large, 14 small) and triangles (8 equilateral, 4 right, 4 isosceles).
• Sparks hours of imaginative free play in children. Anything they can dream, they can create!
• Develops math, science, spatial and tactile skills. STEM approved!
• Safe, durable and built to last for years.