Linus ProAir Aluminum Linear Slot Return with Mud-In Flange - Fully Customizable - 3 Slots Vent Cover

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Linus ProAir Aluminum Linear Slot Return with Mud-In Flange - Fully Customizable - 3 Slots

SKU: LPALSRJ503-E2-12-3-W

Manufacturing time is 2 to 4 weeks.

Linear Slot Return with Mud-In Flange

Complete your linear slot system with the Linus ProAir Linear Slot Return with Mud-In Flange—a fully extruded aluminum return air grille engineered to match your supply diffuser installation. This model features a recessed flange frame designed to be taped and plastered directly into the surrounding drywall or ceiling. Whether you're specifying for a hospital, hotel, office buildout, or high-end residential renovation, the Linear Slot Return with Mud-In Flange delivers a seamless, architectural finish without compromising on durability or performance. One system. One look. Zero visual compromise.

Available in 1 to 4-slot configurations with 1/2", 3/4", and 1" slot widths. Standard and custom sizes available in any length.

Mud-In, Recessed Flange Frame Built with a recessed flange frame designed to be taped and plastered over during installation, the return sits flush with the wall or ceiling surface with no visible trim or frame edge. The result is a fully integrated, architectural finish that reads as part of the surface itself, not a fixture applied on top of it. Ideal for high-end residential and commercial spaces where a clean, monolithic ceiling or wall line is the goal.

100% Extruded Aluminum Construction No steel, no plastic, no stamping, no casting. Pure North American-made extruded aluminum resists rust, corrosion, and moisture—critical for the humidity and airflow demands of any HVAC system. At approximately 15% heavier than standard market alternatives, you can feel the quality difference the moment you handle it.

1 to 4-Slot Configurations Choose the slot count that suits your return air volume and aesthetic requirements. Available with 1/2", 3/4", and 1" slot widths to match your supply diffuser specification and maintain a consistent look throughout the space.

Continuous Run Capability Available in any length. Units over 84" are joined using alignment pins for a seamless, uninterrupted appearance—ideal for long open-ceiling runs in commercial and high-end residential spaces.

Optional Pattern Controllers for Supply Applications Need flexibility in your specification? Add pattern controllers to convert the unit to a supply diffuser application. One product that works both ways, keeping your procurement simple and your ceiling clean.

Field Cuttable Ordered to length from the factory and cuttable on-site using a fine tooth, high speed carbon blade. A maximum of 3" can be trimmed from each end—giving installers the flexibility they need during fit-out. Remove end caps before cutting and reattach once complete.

Multiple Mounting Options Four installation configurations to suit any project requirement: standard screw holes, concealed bracket (+10%), lay-in with no mounting hardware, or fully concealed screw holes. Every option delivers a clean finish appropriate for commercial and architectural applications.

Concealed Fastener Design No visible hardware on the face of the unit. Screws are fully hidden, delivering the seamless architectural finish that specifiers and designers demand in ceiling and wall installations.

Faceplate Profile: 0.055" A slim, low-profile faceplate that sits flush and clean against any ceiling or wall surface—purpose-built for modern interiors where every detail matters.

Finish Options: White, Black, and Primed Choose the finish that fits your project. Available in a durable white powder coat finish, a black powder coat finish, or a primed coat finish with a fine texture that evenly adheres wall paint to the product for a fully custom, paint-matched look. When applying paint to the primed finish, be sure to cover the ice tong louver blades first. Custom colors, sizes, and slot configurations are also available, contact the sales team to discuss your project requirements.

Custom Sizing Available Produced to your exact specifications. Contact us directly for custom length, slot configuration, finish, or mounting requirements.

Linear Slot Return - Specs

Measuring - Dimensions

Measurements

Measurement Chart

Length Considerations

Add 1-1/2" to Length for Overall Outside Dimension
Subtract 1/2" from Length for Overall Inside Dimension

Mounting Options

Screw Holes

Concealed Bracket (+10%)

Lay In / No Mounting

Concealed Screw Holes

LPALSRJ - Return w/ Concealed Frame

Field Cutting

LPALSRJ are ordered to length from factory but can be cut to size in the field. Use a fine tooth, high speed, carbon blade for cutting aluminum.
A maximum of 3" can be cut from each end (X).
For adjustments of more than 2" slide the retaining clip against support.
Remove end caps before cutting and reattach once cut.

FAQs

Decorative resin covers are designed for wall and ceiling applications only — they are not rated for floor use. They're lightweight enough to mount safely overhead and decorative enough for walls where you want more visual detail than a stamped metal grille. If you need a floor register, our wood, metal, and cast iron options are built to be walked on.

Resin covers don't rust like metal, don't splinter like wood, and are significantly lighter than either — which makes them ideal for ceilings. They're formulated to handle the thermal cycling of central air and heat, so they won't warp or crack from temperature changes. Urethane resin is also stable in moisture-rich environments like bathrooms, where metal can corrode and wood can swell.

Yes — unfinished resin covers can be painted to match your walls or trim. However, covers that have already been painted at the factory are non-returnable. If you plan to paint, order an unpainted cover, apply your chosen color after testing on a sample, and install once dry. Standard spray paint adheres well to resin; no special primer is required for most colors.

Yes. Our decorative resin covers are available in standard sizes and hard-to-find dimensions — the same custom sizing program that covers wood and metal also applies to resin. If your duct opening doesn't match a listed size, contact us with your measurements and we'll confirm what's available. Allow approximately 6 weeks for custom resin orders.