I'm just guessing sz L.  May be an XL.  Can't find the hidden tag. I included measurements so you can verify if it will fit.  Thanks for looking 😊   it's in excellent condition

This Lululemon Henley T-Shirt is perfect for the athletic man who demands both style and comfort. Made with stretchy fabric, this solid blue shirt has long sleeves and a Henley neckline. The shirt features the brand's logo on the front, adding an accent to the classic design.

Machine washable and suitable for all seasons, this Lululemon T-Shirt is a must-have addition to any wardrobe. It comes in size L, perfect for the regular-sized man. With its athletic fit and high-quality construction, this T-Shirt is a versatile piece that can be worn for any occasion.