Signet rings, engraved with a coat of arms, owner's initial or the mark used by a merchant to identify his goods are one of the most common types of surviving medieval and Renaissance rings. The engraved bezel of the ring was pressed into sealing wax and this was then fixed onto a letter or deed. They were made of gold, silver or bronze, depending on the means of the owner and continued to be widely used until the 18th century when they were largely replaced by fob-seals, worn on the watch chain.

The silver bezel of the ring is engraved with a star and crescent moon inside a shield shape, the initials PP can be seen above it. This was probably the coat of arms of the family of Pietroch who originated in Pomerania (now in modern Germany and Poland). The initials PP are likely to be those of a member of the family. The hoop is made of horn set with a copper band. Horn, especially the ass's hoof, was believed to protect against epilepsy.

This ring forms part of a collection of 760 rings and engraved gems from the collection of Edmund Waterton (1830-87). Waterton was one of the foremost ring collectors of the nineteenth century and was the author of several articles on rings, a book on English devotion to the Virgin Mary and an unfinished catalogue of his collection (the manuscript is now the National Art Library). Waterton was noted for his extravagance and financial troubles caused him to place his collection in pawn with the London jeweller Robert Phillips. When he was unable to repay the loan, Phillips offered to sell the collection to the Museum and it was acquired in 1871. A small group of rings which Waterton had held back were acquired in 1899.