They are not hairless. Hairless mice look exactly like standard coat babies until they start to open their eyes. At that time, they start losing fur around their eyes, which moves to the whole face, which slowly spreads until the entire body is hairless.
Those are fuzzy hairless which is caused when a mouse is both fuzzy (recessive) and rex/caracul (dominant curly).
Those are fuzzy hairless which is caused when a mouse is both fuzzy (recessive) and rex/caracul (dominant curly).