RV Designer Vent Registers: Sizes, Cutouts & Damper Guide

RV Designer rectangular vent registers help direct air in RV heating and cooling systems. Select by the existing cutout, register face, finish and damper—not by the visible size alone. This guide compares nine stocked models with product links for each exact number.

Compare rectangular register sizes

10 × 2¼ in plastic

H841 (black), H851 (white) and H861 (tan) share the listed slim face dimensions. All have a damper; check the actual mounting opening.

10 × 4 and 8 × 4 in metal

H874/H876 are the wider 10 × 4 in models; H871/H873 are 8 × 4 in. Compare finish and size before replacing one.

12 × 3½ in thermoplastic

H850 (white) and H860 (tan) have a 12 × 3½ in outer face and a manufacturer-listed 10 × 2⅜ in opening. The face size is not the cutout.

Adjustable dampers

The nine products in this comparison have dampers. Match the opening dimensions and airflow path; a vent cover without a damper is not equivalent.

RV Designer register comparison by listed face dimensions

MPN Listed face size Material Colour Damper
H841 10 × 2¼ in Plastic Black Yes
H851 10 × 2¼ in Plastic White Yes
H861 10 × 2¼ in Plastic Tan Yes
H874 10 × 4 in Metal Tan Yes
H876 10 × 4 in Metal White Yes
H850 12 × 3½ in Thermoplastic White Yes
H860 12 × 3½ in Thermoplastic Tan Yes
H871 8 × 4 in Metal Tan Yes
H873 8 × 4 in Metal White Yes
Measure the opening, not just the face. H850 and H860 have a 12 × 3½ in outer face with a 10 × 2⅜ in mounting cutout. For other models, confirm the exact manufacturer's cutout specification or measure the existing opening before purchase. The face sizes in this chart are not guaranteed hole dimensions.

Before installing a replacement register

  1. Remove the old register and measure the opening, depth, surrounding mounting surface and screw locations separately from the exposed face dimensions.
  2. Choose the new register's exact part number, listed size and finish. Do not assume that a 10 × 4 in face fits a 10 × 4 in cutout.
  3. When replacing H850 or H860, note their specified 10 × 2⅜ in cutout, even though the exposed face measures 12 × 3½ in.
  4. Keep the damper and louvers able to move freely. Avoid covering ducts or obstructing airflow.
  5. Confirm manufacturer mounting instructions, suitable fasteners and the intended floor or wall application for the actual product.

RV Designer register products

Each link leads to the matching catalog item for further details.

Compare the numbered products above to your old vent. For unrelated roof ventilation parts, consult the appropriate model-specific RV vent or fan reference rather than assuming the sizes match.

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