Crouse-Hinds series Chico® sealing compounds and fiber are used to form a seal around each electrical conductor and between them and inside of the sealing fitting to restrict the passage of gases, vapors or flames through the sealing fitting. Chico® X fiber forms a dam between the integral bushing of the sealing fitting and the end of the conduit and around the electrical conductors entering the hub. It is a mineral wool that packs easily, forming around each conductor.