Men’s VALENTINO shirt. Unsure of size or fabric as tags are removed

Men’s VALENTINO shirt, made in Italy. Unsure of the size or fabric as tags are removed, my guess on the fabric would be either silk or a polyester blend, unsure. So PLEASE READ THE MEASUREMENTS. Very nice shirt with no rips or stains. SIZE?? Size: ?? Approx. measurements: Pit to pit: 21 inches Sleeve: 23 inches Length: 28 inches *measurements are approximate and taken with garment lying flat* Thank you for looking at my closet!!