Check the listing for details. Primacoustic Offset Impaler for Mounting Broadway Acoustic Panels - 8 count. Condition: New. Listed at 102.99 USD. Primacoustic Offset impalers provide the installer with a simple, quick and effective method of mounting Broadway fiberglass acoustic panels onto studio walls while creating an air cavity behind the panel to increase bass absorption. The Offset impaler features a U-shaped design that elevates the noise-absorbing panel from the wall by 3.5" making it easy to align with typical 2x4 studs. The panel is held in place using a series of sharp protruding darts that penetrate the panel to secure it during installation. To ensure panels do not get dislodged after installation, applying a dab of construction adhesive to the impaler darts during the mounting process adds a level of security and reduces opportunity for tampering.