Available in 3" and 4" I.d. High flow blower bilge ducting Heat and chemical resistant PVC supported by anodized wire helix Resistant to UV and ozone Primarily used for venting of bilge fumes Hose Midnight Marine high-flow blower vent hose(Black) 402 series vinylvent is a oem replacement ducting for any blower or heater system. Heavy duty, flexible pvc hose with wire reinforcement. Anodized aluminum wire support allows the hose to make tight bends. PVC material is self-extinguishing if exposed to sparks or flame. Smooth inner wall allows for greater air flow with less resistance. Resistant to ozone, weather, and sunlight. Commonly used for marine/boat/PWC/RV blower engine compartment ventilation. like trident/shields/sierra international 116-402-4000, 116-402-3000, 116-400-4000, 116-402-3000, 116-402-4003B, 116-402-4003, 116-402-3003B