Auralex Acoustics Metro LENRD Acoustic Bass Traps, 8 Pack, 24" x 12" x 12",Burgundy High density, open-celled acoustical foam. Absorbs low frequencies to smooth out a room's overal bass response. Yields a more balanced listening environment by controlling bass build up and cancellation through out a room. Will not deteriorate or crumble apart over time. Partially formulated out of soy components to reduce petroleum based chemical usage in an effort to curb deopendance on fossil fuels.