The scientific genius of Leonardo da Vinci is brought to life through this articulated model. The invention that inspired this snap-together replica is taken from the pages of Da Vinci priceless and awe-inspiring notebooks. All models are made of plastic and require no special tools. Manuals are very educational and teach how these inventions have evolved into what they are today. Leonardo da Vinci improved upon the already-established catapult design when he introduced his own vision the the age-old military launching device. The plans for the new catapult employed a hand crank that caused tension on the throw arm before releasing a projectile.