Black durable plastic Low profile trim ring only. Used with our Plastic and metal Low profile roof vents
2 – 2″ deep trim ring accepts into inside side cavity of vent from inside trailer. Seals off insulated wall and protects sharp cutout edge
Trim ring commonly used on name brand RV, Toy hauler and fifth wheel campers.
https://dogboxparts.com/wp-content/uploads/2021/03/Plastic-Trim-Dim.pdf Trim Ring cutout template