I bought this toy to demonstrate the working of an automotive gearbox to my 12 year old daughter (she was doing a school project).I found the model very clumsy to assemble (or maybe that was just me!), and also realized that you could do only one ratio at a time! So once assembled, it was tough to show various gear ratios and how that change is done!Also, it was just too small -- very tough to use this as a demonstration piece as well. I am unable to understand how this is even called a toy!Anyhow, I ended using pieces of the model (gears separately, shafts separately etc) to create my own crude example of how things work in a real gear box!