I purchased my Best Brass Warm Up trombone mute primarily for private practice and also for warming up discretely prior to rehearsals. I use it with a large bore Getzen custom 3047 Bflat/F instrument as well as a small bore Shires trombone. Equally at home in both instruments, it produces a soft, pleasant tone and stays remarkably in tune in all registers.
Excellent for use in family home or in an apartment where there may be adjacent neighbours, it is also very compact and light. It can snuggle up inside the bell in the case enabling it to be taken anywhere.
Although some might find it a little pricey, I feel it is a quality product and therefore is good value for money.
I would recommend this product for players of all abilities.