Just FIY on the dust shoes i sell i use 60 cents EVA rubber sheet 1mm or so, found in any chinese shop. On my shoes it could be made into 5 custom length double strips, on a dust shoe like the above, let's say 2. So for 30 cents and some painters tape to hold it on place, you can make much more superior vacuum , custom cut for your current job.

I mean , why are you buying that brush strips that waste vacuum and at the end of the day are no good for all the different bits you would use??