Mm Manufacturing 641R6-12X6X8 Insulated Register Box R-6

Product Description

The MM Manufacturing 641R6-12X6X8 is a standard-size insulated register box designed for residential and light commercial forced-air duct systems. The interior is lined with 1.5-inch ductliner, delivering an R-6 thermal rating that reduces heat gain and loss at the register opening. The box features a snap-rail flange for fast, secure register grille attachment without additional fasteners. With a 4-inch throat depth and nominal 12 x 6 x 8 inch sizing, this box is suited for supply-air terminations in ceiling, floor, and sidewall applications. Licensed HVAC technicians and sheet metal installers handle this fitting as part of new duct rough-in or replacement work.

This register box is used in ducted forced-air heating and cooling systems where an insulated boot is required at the register termination point. The snap-rail flange is compatible with standard lay-in or snap-in register grilles sized to the 12 x 6 inch face opening. Typical install scenarios include new residential construction, remodel work, and retrofit situations where an uninsulated or damaged boot needs replacement. The R-6 lining meets common energy code requirements for supply duct insulation in conditioned and semi-conditioned spaces.

Key Features

• 1.5-inch internal ductliner provides R-6 thermal insulation at the register termination
• Snap-rail flange allows tool-free grille attachment and a secure, rattle-free fit
• Nominal 12 x 6 x 8 inch sizing fits standard residential supply register openings
• 4-inch throat depth accommodates standard branch duct connections
• Lightweight construction at 2.05 pounds for easy single-tech handling during rough-in

Compatibility

Designed as an OEM-style replacement or new-construction fitting for standard residential and light commercial forced-air supply duct systems requiring an R-6 insulated register box with a snap-rail flange at a 12 x 6 inch face opening.

Installation Notes

Installation is performed by licensed HVAC technicians or sheet metal installers. The supply air system should be fully powered down and the air handler or furnace shut off before fitting or replacing any register box. Secure all duct connections to the box collar per local mechanical code requirements, ensuring airtight seals with approved mastic or metal tape. Do not compress or puncture the internal ductliner during installation, as damage to the liner will reduce its effective R-value.

Technical Specifications

• Insulation R-Value: R-6
• Ductliner Thickness: 1.5 inches
• Nominal Face Opening: 12 x 6 inches
• Throat Depth: 4 inches
• Overall Length: 14 inches
• Overall Width: 8 inches
• Overall Height: 6.75 inches
• Weight: 2.05 pounds
• Flange Type: Snap Rail

Standard Information

• Brand: MM Manufacturing
• Manufacturer Part Number: 641R6-12X6X8