The first occurrence exists because indexxx has listed it sets. The second one is manually added by a user. (Possibly added when atkexotics wasn't listed yet.) These two entries should be merged, or the second one should be deleted. In a future version of indexxx, we will delete all these duplicated entries and make sure that it won't be possible to use duplicated entries anymore.
Is there any reason why is atkexotics.com listed twice?
All models are at least 18 years old.