It's a hairbrush with a built-in microphone.
Who would want a hairbrush with a built-in microphone?
No one. That's what makes it the perfect gag gift. That and the fact that it's just $6.99 (today only) on Overstock.
Also makes a great gift for the children of people you don't like. Much more subtle than a drum set.
There are still Singing Hairbrushes available but they're no longer on flash sale; they're now $13.49.