This 'tone adapter' sits on a tom or snare drum and is supposed to significantly reduce the volume to enable one to practise without disturbing others. While the ring neutralises the overtones, it does little to reduce the decibel output. I would not recommend this ring for volume reduction. Fortunately, this ring is very cheap, so I don't regret trying it, but I won't be buying another one.
Ive also preferred the sound of my drum kits with Evans E rings. The sound is dampened particularly on the snare but also on the toms to give what in my opinion is a better, cleaner sound. This 'Clear 2' model i would recommend more so on a floor tom on a tow tuning rather than a snare drum - on a snare the sound could be dampened too much and deterioratr sound quality. Whereas my 14" floor tom sounds excellent with this ring.
If there is unpleasant higher frequency sound (created due to the geometry and material quality of the drums), these rings definitely adjust and make it sound more tuned (slightly bassy and pleasant sound for me). I like them and still use them : )