This is a Pendleton Burnside button-down shirt. The "Burnside" line is named after a historic street in Portland, Oregon, and is a modern staple in Pendleton's collection.
Shirt Details
Model: Burnside
Material: 100% cotton flannel, double-brushed on both sides for softness
Color: Grey Heather (specifically, "Cedar Heather" or "Natural Heather" in similar catalogs)
Size: XL (Extra Large)
Origin: Made in China

Key Features
The Burnside is known for its rugged but soft construction, featuring two button-through chest pockets (often with a pen slot), a locker loop on the back yoke for hanging, and a twill-taped placket for added durability. While Pendleton is famous for its wool, the Burnside specifically uses mid-weight cotton flannel.