Superlux HD668B Specification

Hello! I've reviewed the product details document for the Superlux HD668B headphones. This document outlines the features of these headphones, including their high-resolution drivers, detachable cables, and comfortable design. I'm ready to answer your questions about the HD668B.
What type of headphones are these?

What is the impedance of these headphones?

What is included in the box?