From the product description:
Detailed instructions and high quality hardwood pieces that have been pre-cut and pre-drilled are all provided, so you can construct a finished model in a day.
This kit is professionally engineered, designed and manufactured in the USA. Made with 100% hardwoods, each part is precision carved by computer controlled machinery for a guaranteed fit and accuracy.
Here a link to see more about the Floating Arm Trebuchet.