The useful decision here is fit. Regular gives you more room through the body, and Slim trims it down without changing the fabric or features.
The Pueblo Long Sleeve is a performance flannel fishing shirt from Poncho. It uses a medium-weight fabric aimed at durability, with stretch for easier movement. Poncho also positions the fabric as moisture-wicking and quick-drying, which helps when the day runs warm or you’re in and out of the boat. Details are fishing-specific: a built-in lens cloth, a sunglasses holder, and a hidden zippered pocket for small carry. This is a flannel feel with technical intent, not a thin sun shirt.