I have an E&L hard brass catcher that only fits ARs with built-in carry handles. I never liked it because I always ended up with smoke in my eyes. I drilled a bunch of 1/4" holes in the front of it, and diagonally across the lower right half for ventilation. But I still had smoking brass setting there in front of my face and quit using it. Later on I bought a Wook Company, Patent Pending, Made In USA brass catcher, AR-15 flat top. "Competing, dogging or an afternoon of shooting enjoyment. Brass is worth saving. Reloading your empties, saves money, improves accuracy. If you do not reload now, you will. Do not leave your brass behind." It's a solid nylon bag with a wire frame inside, that attaches to the forend with a 2" wide Velcro strap, and has a non-slip pad sewn onto the strap. The bag is only attached to the strap at the top of the frame, and the bottom can flex outward if it needs to. It has a zipper on the bottom at the rear so you can leave it attached to the gun and empty it, or leave it open to drop your brass in a pile on the ground as you shoot.
I don't use this one either, and can't find out anything about the company. When I search for "Wook brass catcher", I find Caldwell brass catchers and everyone else. I should use it, with the bag zipped open to dump my brass in a neat pile, instead of flying all over. I don't know where it will end up with the Tubb Precision Chrome Silicon "more efficient" ejector springs, and 80-percent greater power extractor springs. I don't reload, but I like to clean up after myself.
https://www.davidtubb.com/ar15-tubb-parts/ar15-extractor-ejector