Framing support strips that are used on inside of roof with our patent pending outside vent adapters. Length is 38". Strips will need to be cut to fit the span between the cross members where you are installing your fan.
Dimensions for the support strips are:
Sprinter .75" x 1.5" x 38"
Promaster .75" x 1.3" x 38"
Provides material for screws to engage as they penetrate the roof metal. Made from expanded PVC so will not rot, mold or absorb moisture which is typically found around the vent.
The framing strips are expanded PVC and bonded to the roof with a thick bead of Windoweld. They are more flexible than wood and plenty strong to support the vent and keep it from jiggling. They are essential if the span between the OEM roof beams is more than 18". They also provide a backing for the screws that hold up the vent interior bezel. They should be placed 1/4" away from the edge of the hole so the screws for the vent go into the strips.
If you have questions about this product you can call Hein at 541-49O-5O98