This appears to be a simple looking band of silver. When worn and attuned, however, the ring can change form to appear like any other kind of ring the wearer wants.

While worn and attuned the ring grants the wearer the ability to cast Alter Self upon themselves at-will as a Bonus action and maintain the duration indefinitely - the duration becomes "until dispelled or dismissed". The spell can be dismissed as a Bonus Action. The spell Dispel Magic cast upon the wearer or ring against this effect will dispel the effect and surpress any future use of the ring for 1 hour.

Also while the ring is worn and attuned the wearer is considered a shapechanger and immune to spells that transform the body such as Polymorph, True Polymorph, etc.

Notes: any humanoid creature, Movement, Utility, Exploration, Combat, Shapechanging, Deception, Jewelry