RECOIL AP4 4-Inch Aero Port Kit, Flared Bass Tube, Heave Duty ABS Material Flares, 5.8mm Reinforced 12” Cardboard Pipe, Low Turbulence Design, Subwoofer Enclosure Upgrade

Flared Design: Proprietary aerodynamic flares reduce air turbulence by 70% vs. standard tubes, eliminating chuffing sounds. Distortion-Free Lows: Experience punchier, deeper bass without unwanted noise pollution. Adjustable Length: Cut the heavy-duty reinforced cardboard pipe (12 included) to any size for perfect box tuning. Cut-to-Fit Flexibility: Recoil’s AP4 aero port seamlessly integrates with standard 4-inch PVC pipes (readily available at US hardware stores). Customize vent length in minutes for perfect bass tuning. 5.8mm Cardboard Core: 2X thicker than competitors (industry avg: 2.5mm) resists box compression. ABS Flare Armor: 3.2mm wall thickness survives 200+ lbs pressure | Humidity-proof