The covers are made out of a proprietary thermal barrier material. It is not the course welding blanket used by some companies.  They are sewn with nomex thread. They come slick without webbing or with webbing.  I also supply a shock cord for tightening the cover to your suppressor.We have thoroughly tested these covers.  They  are made as a mirage shield to allow you to shoot longer before the noticeable affects of mirage  from the heat  coming off your suppressor.  We have tested these with many strings of rapid fire.  They hold up.  You can however destroy them if you abuse them in that manner.