Each tube contains 16 Pixio magnetic blocks in one color.
One PIXIO block is a plastic cube 8 x 8 x 8 mm in size, weighing just over 1 gram, which has 6 magnets inside. The polarity of the magnets is designed in a way that the blocks can be connected to each other in any sequence from different sides [patent pending].
Just take the PIXIO block in your hand and place it where you want it to be - BANG! - the PIXIO block is connected.
Only 3 left!