Wallace TWC-M19C Practice Compact

This is a lightweight, very durable mute that fits right inside the bell, so can be transported easily in your case.

The attenuation it provides is perhaps a little less than some other products, but it produces the best accuracy in tuning and tone of any practice mute I've used before. If you need to practice whilst others are sleeping it might not be the best choice, but it's still quiet enough to keep all but the most fussy neighbours happy.