Magformers is a famous magnetic building kits brand from the USA.
Magformers sets contain plastic frames of different shapes, like triangles, squares, rectangles and so on.
All of them have small but powerful magnets sealed inside the edges, so you can connect the pieces in any way you want.
The magnets of the original Magformers pieces are always strong enough to keep even big sculptures together, and more reliable structures can be actually survive a light toss without falling apart.
Some kits have special parts like propellers or rechargable LEDs, which kids can also add to their magnetic creations.
Despite different shapes, you can use any Magformers sets together, regardless of their style.

Built by Sam, 5 years old. Recently Sam has been very passionate about creating urban landscapes with high-rise buildings, cranes, playgrounds, etc. Sometimes he uses not just building kits, but also all sorts of improvised materials such as cups, lids. IMO, it turns out fresh and interesting.