AlphaSorb™ Fabric Wrapped Acoustical Bass Traps are low frequency bass absorbers that answer your acoustical and aesthetic needs with their strong sound absorbing performance, durability and elegant appearance. They are designed to fit into a corner of a room. They come in 2' and 4' heights and both have a 12\" depth. The installation of these acoustical bass absorbers is quick and simple. They can simply rest on the floor in the corners, be adhered with water based panel adhesive or velcro into place. The standard fabric used on them is the Guilford of Maine FR 701, Style 2100 line. These acoustical bass traps are class 1 fire-rated and are often used in the Broadcast and Recording Industries, Home Theaters and Houses of Worship