project specifications; specs
Technical term used in engineering, construction, and manufacturing to refer to detailed design documents.
We ordered the parts according to the project specifications.
The material strength is described in detail in these specs.
仕様書 is a broader term for specification documents, while 設計明細書 specifically refers to design specifications.
Compound of 設計 (design) + 明細 (details) + 書 (document).