Vater Buzz Kill
Sticky little discs about 1½" in diameter, Vater's Buzz Kills take the same approach to drum head discipline as RTOM Moongel.
Extremely squishy and tacky, they'll stick to both batter and resonant heads and are surprisingly effective at eliminating unwanted sustain. Even a single Buzz Kill makes a noticeable difference to the cohesiveness of a drum's tone. If you really push the boat out and use two or even three together, you can really go to town in terms of shaping your tones.
Very adhesive and surprisingly effective.
Nothing of note.
Another perfectly good option for dampening your drum sound.
Removable EQ Muffle Ring