Tractate Yevamot - Chapter 8 - Mishnah 2 יבמות פרק ח׳ משנה ב׳

Who is considered a “petzua dakkah”? Anyone whose testes are wounded even one of them. And a “kerut shofkhah”? A man whose member is cut off. If [any part] of the corona remained, even so much as a hair’s breadth, the man is regarded as fit [to serve as a priest]. A man who testes are wounded, and one whose member is cut off, are permitted to marry a convert or a freed slave. They are only forbidden to enter into the congregation, as it is said “No one whose testes are crushed or whose member is cut off shall be admitted into the congregation of the Lord” (Deuteronomy 23:2).