There are generally two types of telecommunications cables in use: copper wire and fiber optic. Both types require materials that serve as filling compounds, which space the conductors, and flooding compounds, which flood the armor layers within the cable. These compounds, which also provide water-proofing for the interior components of the cable, are generally hydrophobic hydrocarbons that can be injected hot during cable manufacture. They must also remain flexible at low temperatures. Eastman recommends several products as raw materials in the formulation of filling and flooding compounds, including Eastotac hydrocarbon resins, and Eastoflex amorphous polyolefins.