Sierra Shieldsflex II 5 WaterExhaust Sierras Shieldsflex II Marine WaterExhaust Hose has a black synthetic rubber tube and cover. The Shieldsflex II is primarily used for engine intake, bilge pump intakedischarge, scupper lines. Features Reinforced with wire helix embedded between plies of HD synthetic cord. Resistant to exhaust fumes, ozone, mild chemicals, antifreeze and saltwater. This hose is abrasion and odor permeation resistant It now has double the ozone resistance required by the SAEJ20