Cannot be Destroyed
"This contains a fragile whistle that can be used to summon a ridable horse. NOTE: Once opened you can only use the whistle to summon a mount for 24 hours (tracked in real time)."
Open the Gift Pack you received in the mail following the completion of the Introductory series to recieve this item.
Opening this item creates the Tarnished Whistle (Average Steed, 24 hrs.).