If your drums are tuned well but still sound like a ringy mess.. BUY THESE!
I have both these and e-rings, and much prefer the moongel. The gel just sits on the outer edge of the batter head, or can be cut for more options. It stops the buzzing and over ring of drums, without crushing the sound and making them sound like a dull thud.
I found the e-ring over dampens the drums, which can be good for really troublesome ringing, but it often sounds a little too over the top. The moongel lets you hear the natural sound of the drum, just in a more controlled sound.
Still sticky after a few months and after a wash!