Very light, excellent mute. Blows more freely than the Brenner ssshmute (which is also a fine practice mute, but I prefer the Voigt). You don't even notice the mute is in, so it keeps the trombone in balance. Only the low notes are a little out of tune (from the lowest Bb down). The Studio mute of Wallace does a better job with that, but is too heavy for long practice sessions.