The Auralex 2" Studiofoam Wedge comes in a variety of colors. They are great overall noise absorbers! Use "em to treat small- to medium-sized areas including vocal booths, control rooms, and sound studios. They effectively kill standing waves and flutter echoes and - when used in conjunction with LENRD or Venus Bass Traps or Sunburst Broadband Absorbers - can effectively tame the full frequency bandwidth in virtually any room. 2" acoustic Auralex Studiofoam is an industry workhorse and is your safest bet if you"re tuning your room yourself without the help of a professional acoustician. For installation, Studiofoam Wedges require of Auralex Foamtak spray adhesive box (sold separately, - see #422605), which allows you to remove the foam later. For more permanent installation use Tubetak (sold separately - see #422606) or Tubetak Pro liquid adhesive applicators (sold separately - see #472436). 1 Foamtak covers up to 96 square feet. 1 Tubetak/Tubetak Pro covers up to 24 square feet. Includes 12- 2" x 4" foam pieces (96 sq. ft.).