Dust boot brush material

Has anyone used this type of brush material for your custom dust boots?

Looks to be about 3" - 4" tall & around 3’ long, should be enough to make a few spares.
Wondering if it’s too stiff or not stiff enough.

Yes - I bought some from Amazon to build a dust shoe for my OneFinity - I think it was 2" but I trimmed it even shorter. Works great. I didn’t like the design/vulnerabilities of the ‘Suck-it factory set up’ Charlie