An attachment device for a finger ring for improving the fit of the ring is constructed from a clamp, an elongated spring secured by the clamp, and a resilient sleeve disposed upon the spring. The clamp is of monolithic construction, fabricated from a piece of thin sheet stock of a malleable metal and having a base portion elongated between two extremities and adapted to be bent so as to lie against the interior surface of the ring. At least two gripping portions extend from the extremities of the base portion. A bracket portion, which secures the spring, extends from one extremity of the base portion in a direction opposite to the gripping portions.