The phrase "specification details" refers to the specific information or requirements about something. It includes all the specific facts, measurements, features, or instructions that are needed to understand or build something. Full definition
We'll have full pricing and specification details as they come to hand. (ausmotive.com)
But, the company still has not made all the technical specification details official yet. (techtree.com)
We work with all valued customers to develop required wine specification details, which can later be used to form part of the purchase terms. (ciatti.com)