I purchased this like most brass players as a way to practice without annoying the whole household.
Overall, it is a great option with more pros than cons and far better than most practice mutes. I know some players dislike this type of system, but if the alternative is being unable to practice, then it is a no brainer.
What you get is an electronic mute attached by an audio jack into the control unit. The sound it then output via a set of wired headphones. There are a number of options on the control unit for use in a room or a hall, both give excellent sound feedback, with the room setting offering a more resonant feedback. which is very accurate.
This package comes with and adapter ring which allows you to use it with a bass trombone, (or an english style baritone horn. I can't really comment on the yamaha studio option at this point as I haven't used it.
The family think it works great as they can't hear me when practicing in a bedroom and it enables me to practice at various times of the day.
The only reason I have reduced it to one star is that, overall the unit feels a bit like a cheap walkman, very dated design and the controls are a slide and knob type. It feels like a very analogue unit, absolutely no digital displays etc. Finally, the headphones supplied have a lack of quality about them and as they are wired you have to ensure you don't get tangled up. The unit is able to attach on to your trouser belt so you can move around with it.
It could really be improved by Yamaha with a re design bluetooth function, wireless headphones and mute, but cost may be prohibitive.
Overall, it does exactly what it is advertised for, I recommend it and I would absolutely buy again and Thomann as always were excellent in terms of delivery