Wolf eliminators are often installed on the cello G or D string to compensate for the wolf vibration in an instrument. It is easy to install. Place between the bridge and the tailpiece. The player will likely need to adjust the eliminator higher and lower on the chosen string (behind the bridge) to find the "sweet spot" where the wolf is eliminated.

Wolf-Be-Gone - Wolf Eliminator by Super-Sensitive. For Violin or Viola. Easy installation.