I wear it under my uniform shirt in winter. It's quite thin but very warm. My only complaint is that I'm sorry I can't order the large version as I'm over 6ft 1in and the regular one isn't very long.
Men'S Long Sleeve Polo Shirt - Slim Fit, Stretchy, Breathable Collar
43 Review
H2H Mens Casual Slim Fit Short Sleeve T-Shirts Cotton Blended Soft Lightweight V-Neck/Crew-Neck
46 Review
Calvin Klein π Herringbone Sleeve Men's Dress Clothing
50 Review
Van Heusen Traveler Stretch Men's Shirt
47 Review