The Bowjax Ultrajax II String Silencer has been Bowjax" s most popular model with bow companies and consumers for the past two years. It"s been a top seller because of its effectiveness and ease of use. Ultrajax II slip over the bow string to effectively dampen the oscillation that occurs after the shot. For compound bow users that are looking for even more dampening ability, attach an Ultrajax II to your cable.