Here are proven ways to seal fiber joints: Use armored cables with extra layers to block moisture and rodents. Pick dome-type closures for buried joints. Many NEMA and IP-rated potted seals, grommets and cable glands can shield fiber optic components from water spray or temporary submersion at a limited depth, but they fall short of a moisture-tight hermetic seal and will allow gases and water vapor to transfer from the outside of a sealed system to. HELIAX ® SureGuard ® sealing adpapter for fully threaded device ports. Our fibre optic seals will defend against water, gas, rodents, and other destructive hazards. As well as our extensive portfolio of out-of-the-box products, we can also tailor solutions to your unique challenges. Protecting them is essential for long-term reliability.