I build & repair valve amps, so I use these a lot when modifying or making amp combos.
These look good and certainly protect your fave speakers from any damage, much more than cloth.
These also let all the sound get away from your speakers far better than any cloth covers (tested with mt DB meter). OK, just a couple of decibels, but every little counts when the venue is full of talking/shouting people.
These two 8 inch speaker grilles are being used on an acoustic amp that always rides with me in my van & will be tested many times as I carry lots of other junk in the van, so any quick braking or cornering is the test as my amp rolls around sometimes. These are good and will easily take some abuse.
Thomann price and delivery times easily beats any local music shop.