The performance ear seals fit all current Lightspeed headset models (Zulu Series, Sierra, and Tango) and are designed to hug the curve of the jaw, creating a more natural fit that increases your comfort and stability. The head pad is the standard sized head pad that comes with the Zulu Series. The Mic Sock fits all current Lightspeed Zulu Series, Sierra, Tango and PFX headset models. All Lightspeed headset mics are calibrated for use with a wind screen.