Dorrough produces a variety of digital audio meters, video meters, surround sound meters, and audio and video test products. A no-hassle one year warranty is standard on all Dorrough products.   The company is located at 5221 Collier Place, Woodland Hills, California 91364 • Telephone (818) 998-2824. Fax: (818) 998-1507. Email: dorroughel@aol.com