These are great for toning down that ringing drum. If you have ever turned up for a gig or in the studio and you cannot get that tom to stop making a funny noise, then these are for you.The E-Ring is an easy-to use external overtone control ring which "floats" on the surface of a drum head. It removes overtones and flattens the drum head's sound and allows for easier tuning. E-Ring Prepacks are also available to match the most common drum set configurations. Available in different sizes.