Mine was a gift from my wife. I didn't read the link and I'm sure it's in there, but superstition states that you are supposed to receive yours as a gift. You're not to buy it for yourself. Also, they are most definitely not exclusive to Harleys.
I've been bell-less all my biking life ...and I've never even driven a Gremlin. Though, a high-school friend of mine did own a Pacer (which is, quite possibly, ever-so-much worse than a Gremlin).
Mine was a gift from my wife. I didn't read the link and I'm sure it's in there, but superstition states that you are supposed to receive yours as a gift. You're not to buy it for yourself. Also, they are most definitely not exclusive to Harleys.