Magnets are such great fun! When combined with a great construction toy like Smartmax, the learning outcomes are endless. The pieces in Smartmax are huge. The bars are of various lengths but are 25mm in width and the connecting balls are a massive 40mm in diameter. You can build almost anything. It really is up to the childs imagination and creativity. All kits come with an instruction book and a suggestive set of objects to build. All of pieces and kits are compatible with each other.