Pithi's Ornamental Ring is an item in The Elder Scrolls V: Skyrim.
Use
At the Midden Dark the ring is used, with the other three, to release the Daedra Velehk Sain. In order to summon Velehk Sain, the rings must be placed in the following order: Little Finger: Pithi's Ring, Ring Finger: Balwen's Ring, Middle Finger: Treoy's Ring, Index Finger: Katarina's Ring.
Location
It can be found in The Arcanaeum at the College of Winterhold inside a chest.