Certainteed - CertaSound™ Acoustical Insulation
CertaSound™ Sound Attenuation Batts : CertaSound Sound Attenuation Batts are for interior walls.  They are un-faced fiber glass batts designed for use in steel or wood construction to improve acoustical performance in residential and commercial applications.  They are slightly wider and longer than conventional fiber glass batts. 
CertaSound™ Acoustical Ceiling Batts: CertaSound Acoustical Ceiling batts are designed to lie directly on suspended ceilings, providing excellent thermal protection and acoustical performance.  They are available un-faced or with a kraft facing.  Kraft-faced CertaSound Acoustical Ceiling Batts, due to application, have no stapling flanges. 

For more information about Acoustical Insulation, please visit Certainteed at http://www.certainteed.com/pro/insulation/product/index.html