This classic button-up is made with a durable cotton construction and features a convenient button-closure chest pocket. Stylish and ready to go, this short sleeve is naturally comfortable, it's made from 100% cotton that wears well with age. A button closure chest pocket keeps items close by and handy. Columbia offers this men's shirt in multiple patterns and sizes. Regular Fit. To ensure the size you choose is right, utilize our sizing chart and the following measurement instructions: For the chest, measure at the fullest part of the chest, under the armpits and over the shoulder blades, keeping the tape measure firm and level.