Some sort of Bell, I think.
$10 at K-Mart, if my memory isn't playing tricks on me.
I was in college when I bought it, which means it can't be more than 15 years old, is definitely more than ten years old, and won't be replaced until I fall on my head. That's happened three times, and the time when I was wearing a helmet (the second), while not pleasant, was definitely the least unpleasant.