Lightspeed's Performance Ear Seals fit all current Lightspeed headset models (Zulu Series, Sierra, and Tango) as well as the PFX, 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 and PFX headsets*. The wind screen (mic muff) fits all current Lightspeed Zulu Series, Sierra, Tango and PFX headset models. All Lightspeed headset mics are calibrated for use with a wind screen.