Ecmo asked, "Dang just gotta ask, is that for a man or woman?"
My typical "super-close observation of the object's characteristics" analysis says it's for a female. In the photo, the object is tilted back. If it was shown oriented at the angle it would be worn at, the toothed opening is too low down for a male's organ to fit into, but just right to correspond to the location of a female's genitalia.
Note that it has two crude loops at the waist for padlocks.
Additional evidence that it is for a female: It appears to be quite old. Chastity devices for females go back many-many centuries. Chastity devices for males seem to be almost entirely a 20th-Century (to present day) kink.