It took approximately two years to design this spectacular magical art for you to put together. This “V12 f our-stroke Engine” has semi-realistic exterior and interior detail. Each of 12 s park plugs (LEDs) is ignited accordingly to the moving cycle. Many moveable parts include a compound crankshaft, a rapid cooling fan, 12 rods and 12 pistons etc. It is made with paper entirely (except some little wood sticks, some tapes, 12 LEDs, some electrical wires, 12 switches, a resistor, a motor and a battery holder ) . The instruction included in this kit is a PDF file contains easy-to follow diagrams and step-by-step instructions with more than a thousand detailed nice and clear pictures. No paint applied. It looks pure and elegant. Various shadows created by different light sources make it look stunning. The origami-reinforced structures are applied inside the engine. They make the model very rigid and keep the pieces in the accurate positions.