Sonance DISC Invisible Series System Depth Sensing Gauge For IS SpeakersThe Sonance DISC System is a depth sensing measurement tool for Invisible Series speakers, allowing the installer to verify finish thickness over the speaker before the wall or ceiling is signed off. The system uses a high accuracy depth gauge paired with embedded locator discs to measure the thickness of plaster, paint, or wallpaper applied over the surface of a Sonance Invisible Speaker. Verified finish depth keeps acoustic performance within