"羊毛制的覆盖物" can be translated into English as "woolen covering" or "wool covering".
"Woolen" is an adjective derived from "wool," specifically referring to something made of wool.
"Covering" here denotes an object used to cover something else.
Both expressions are accurate, but "woolen covering" might be slightly more precise in emphasizing the material (wool). However, in everyday usage, "wool covering" is also perfectly acceptable and commonly understood.