- Features: These a suitable choice for environments with substantial noise such as working with power tools. The sealing rings are filled with a unique combination of liquid and foam. The result is an optimum seal with low contact pressure, which provides agreeable comfort even during long-term use. The sealing rings have ventilation channels and are covered with soft, patterned, hygienic foam. A suitable choice for environments with substantial industrial noise or construction machinery, like airports and agricultural work.