Ultra Double Bass Mute

It does its job alright, it takes some off some of the volume of your double bass, but it'll make more of a difference to when you are playing arco than pizzicato. In pizzicato it will mean of course shorter sustain and in arco a considerable loss of harmonics since this will muffle up the sound quite a bit.
However, it does what it was made for: to play without bothering the neighbours!

Hoped it would mute the sound a little more than it does. It more dulls the sound by reducing high frequencies rather than mutes it. It definitely helps our neighbours ears a little, though.

but it leaves some black marks on the bridge