This is a good quality bit of kit. Foam on the inside, fur on the outside, with a rubber neck to ensure it grips onto the mic. There's a little accessory, a rubber O ring supplied too, which is to cover the USB-C port while the mic's in use, to ensure you don't get any wind noise whistling across the hole. I must confess that I haven't had an opportunity to use this muff yet, but it looks well made, from good materials - a semi dense foam inner, and a densely packed, long fur, so it does give me confidence that it will do what it's supposed to. But I'll update, or add a second review if I get disappointing results after testing it in windy conditions. At this point in time however, I'm very glad to have in my array of gear, for those outdoor run and gun interview situations. A bit pricey, but if it works as I expect it to, well worth it. The Rode Go II or whatever it's called provides fantastic audio quality for the price, and it's so light (not having an internal battery) it sits on top of my camera-gimbal set-up very nicely.