I'll have to disagree with the previous reviews. Firstly, the good: these guards are inexpensive, and they arrived super-quickly despite being sent from China. Now, the bad: the guards that I received were rather soft, and four of the guards had a mesh that was way too open. The brushes couldn't be dried upside down in them because the mesh was not strong enough to support the weight (unlike another popular but more expensive product, which has much higher density and strength). The ones that had a very open weave would get the bristles poking out, and thank goodness that I checked them because the brushes were drying with bristles coming out even if they were laying flat... in the end I had to remove them completely from those and change them into other guards.
Overall, they weren't a total waste of money, but I don't trust them to keep my brushes safe for travelling, they are too soft, or any vertical drying. For flat drying, the smaller mesh seems to be OK although it also requires some supervision during the process.