Accordion Boot Installation Readiness Checklist

1. Opening Shape & Alignment

Both openings are the same basic shape. Both openings are aligned with each other. Both openings have the exact orientation and perimeter size.

2. Corner Radius

Corners have at least a 1 inch radius or a 45 degree transition. (More is better) There are no sharp 90 degree square corners.

3. Flange / Mounting Surface

Both openings have a thin wall or flange approximately +/- 1/8 inch thick. Not to exceed 3/16" The flange is fairly straight with few bends. The flange provides proper support around the opening.

4. Parallel Surface Check

Facing walls are mostly parallel. Gap variation from top to bottom is within about 2 inches.

5. Perimeter Measurement

Both openings have the exact outside perimeter measurement. Width, height, and total perimeter have been measured.

6. Gap Distance

Measure the distance between the two mounting surfaces at the top and bottom of the opening.

7. Movement / Flex / Articulation

Expected movement level: Minimal - highway use / rigid mounting Moderate - normal truck or camper use Extreme - off-road, frame flex, or heavy articulation

For extreme movement, the calculator deducts 1 inch from the measured gap before recommending a boot size.