Lambro Industries 418 Flexible Duct 4 in X 8 Ft Aluminum

Product Description

The LAMBRO INDUSTRIES 418 is a 4-inch diameter, 8-foot length aluminum film laminated flexible duct designed for low-pressure air distribution in residential and light commercial HVAC systems. Constructed with an aluminum film laminate outer layer, this flex duct provides a lightweight, pliable connector between rigid ductwork and supply or return air boots. It is intended for use as a transition or short-run connector and is not a substitute for rigid metal duct in main trunk or high-velocity applications. HVAC technicians and installers handle this product during new construction, retrofit, and equipment replacement work.

The 418 flexible duct is suited for residential forced-air systems, including gas furnace, heat pump, and central air conditioning installations. It is commonly used to connect branch runs from a plenum or trunk line to individual supply registers. The 8-foot length gives installers enough material to route around framing members and make directional changes without over-stretching the duct. Each unit is sold and packaged individually for straightforward jobsite use.

Key Features

• 4-inch diameter fits standard residential supply branch fittings
• 8-foot length allows flexible routing without splicing short sections
• Aluminum film laminated construction provides a lightweight, semi-rigid outer shell
• Pliable core supports bending and repositioning during installation
• Not a substitute for rigid metal duct — intended for connector and short-run applications
• Individual carton packaging keeps product clean and undamaged on the jobsite

Compatibility

Designed as an OEM-style replacement and general-purpose flexible duct connector for residential and light commercial forced-air HVAC systems using 4-inch diameter branch duct fittings.

Installation Notes

Installation should be performed by a licensed HVAC technician in accordance with SMACNA guidelines and applicable local mechanical codes. Power down and lock out the air handling unit before connecting or disconnecting ductwork. Avoid sharp bends, compression, or over-extension of the flex duct, as these conditions reduce airflow and system efficiency. Secure both ends with approved clamps or draw bands and seal joints with listed duct tape or mastic sealant.

Technical Specifications

• Diameter: 4 inches
• Length: 8 feet
• Construction: Aluminum Film Laminated
• Weight: 9 pounds
• Package Quantity: 12 per case
• Unit of Measure: Each

Standard Information

• Brand: LAMBRO INDUSTRIES
• Manufacturer Part Number: 418