Noble's Eternal Elementium Signet
Sold by Haris Pilton. CANNOT find this item on Haris Pilton as of right now. She does have the Eternal Black Diamond Ring toy.
The 
Noble's Eternal Elementium Signet is a Toy sold by Haris Pilton in Shattrath City during The Burning Crusade expansion, available in limited quantity and requiring some vendor camping to purchase.
Guide awaiting review
Locate Haris Pilton
Find Haris Pilton at 35.8, 20.6 in Shattrath City — she can be found inside the World's End Tavern in Outland.
Purchase the Toy Ring
Buy the Noble's Eternal Elementium Signet for 
3500 Gold. This item has a limited quantity of 1 and respawns approximately every 10–15 minutes, so you may need to wait at the vendor if it has recently been purchased. Be careful not to accidentally buy the similarly named Noble's Elementium Signet for 2400 Gold — that version is not a Toy and both items share the same icon, appearing right next to each other in the vendor window.
Tips
The Toy version costs 3500 Gold and includes the word 'Eternal' in the name; the non-Toy version costs 2400 Gold and does not.
