Air Flow Products 7740804 Straight Register Boot 4x8 4in Collar

Product Description

The AIR FLOW PRODUCTS 7740804 is a straight register boot designed to connect rectangular duct openings to floor, wall, or ceiling registers in residential and light commercial HVAC systems. This boot features a 4x8 inch rectangular register opening and a 4 inch round collar for duct attachment. Straight register boots serve as the transition fitting between branch duct runs and the register face, directing conditioned air into the occupied space. HVAC installers use this fitting during new construction and retrofit duct work where a straight-through airflow path is required.

This register boot is suited for residential forced-air heating and cooling systems where a 4 inch round branch duct feeds a 4x8 inch floor or ceiling register. The straight configuration keeps airflow aligned without an offset, making it a straightforward choice for layouts where the duct approaches the register from directly below or behind. It is commonly installed in wood-framed floors, ceilings, and interior wall cavities.

Key Features

• Straight boot design provides direct, aligned airflow path from duct to register face
• 4x8 inch rectangular opening fits standard 4x8 inch floor and ceiling registers
• 4 inch round collar accepts standard 4 inch flexible or rigid round branch duct
• Series 77 designation identifies this as part of the AIR FLOW PRODUCTS boot line

Compatibility

Designed as an OEM-style replacement or new-construction fitting for residential forced-air HVAC systems using 4 inch round branch ductwork feeding 4x8 inch registers.

Installation Notes

This fitting is typically installed by HVAC technicians or sheet metal contractors during duct rough-in or system retrofit. Shut down and lock out the air handler before working on duct connections. Secure the collar to branch duct with sheet metal screws and seal all joints with UL-listed duct mastic or foil tape per local mechanical code requirements. Ensure the boot is fastened securely to the framing before installing the register face.

Technical Specifications

• Register Opening Size: 4x8 inches
• Collar Diameter: 4 inches
• Boot Configuration: Straight
• Series: 77

Standard Information

• Brand: AIR FLOW PRODUCTS
• Manufacturer Part Number: 7740804