Shields Vac Standard Hose is PVC, supported by vinyl-covered steel wire, and is very flexible. It is nylon- reinforced and is resistant to mild chemicals and saltwater. This hose is primarily used for bilge pump intake and discharge, diaphragm-style hand-operated bilge pump intake and discharge, and drains (sinks, shower, and scupper). This hose uses 142 left hand thread cuffs. Do not attach to thru-hull fitting below the water line. Sierra Part #116-140-1126.