This is an improved version of our standard MDF speaker rings, made from high-density urethane which has many benefits over wood-based products. In addition to a 66% weight savings vs MDF, this material is dimensionally stable, dampens vibrations better, and is impervious to water. And because it's not as hard as MDF you can mount your speakers without the need to pre-drill pilot holes when using the self-starting deep-thread screws that we supply. If you need more than 4 screws for each speaker we suggest you purchase an extra pack of 8 screws from us, as not all "wood screws" will hold well in this material.
Note - While we believe these speaker rings are superior overall to our MDF product they are not as strong as wood, and if abused they can sustain physical damage. So try not to smash them with blunt objects, poke them with sharp instruments, or run over them with your car.