Our Performance Ear Seals fit all current Lightspeed headset models (Zulu Series, Sierra, Tango, and PFX) and are designed to hug the curve of the jaw, creating a more natural fit that increases your comfort and stability. To ensure peak ANR performance and comfort, we recommend replacement of the soft goods on your headset (ear seals, head pads, and mic muffs) every 18 months.