Trident Marine 481-4000 Heavy-Duty Polyduct Blower & Vent Hose 4" ID x 50ft Blue

The Trident Marine 481-4000 is a premium, heavy-duty polypropylene blower and vent hose designed for marine heat, ventilation, and air conditioning (HVAC) applications. Built to handle the demanding conditions of a boat's engine room, bilge, and cabin ventilation systems, this 4-inch inner diameter hose delivers reliable airflow where it matters most.

Key Features:

• Heavy-duty polypropylene construction — durable, lightweight, and completely rust-proof
• Polypropylene helix rod reinforcement — maintains shape under compression and resists crushing
• Excellent flexibility and compressibility — routes easily through tight spaces, overheads, and bulkheads while delivering full airflow
• Smooth inner wall — minimizes air resistance for greater flow efficiency
• Crush-proof design — step on it, and it springs back to its original shape without damage
• Resistant to flex fatigue, tearing, and moisture condensation — built for the marine environment
• Wide temperature range: -40°F to +225°F (-40°C to +107°C) when insulated
• Meets FMVSS 302 flame resistance standards

The 481-4000 features a 4-inch inner diameter and comes in a 50-foot boxed length, making it ideal for HVAC duct runs, engine room blowers, bilge ventilation, and cabin air systems. The blue color is a standard identifier for marine vent hose applications.