The 409GSM (12.1oz per square yard) Double Heavyweight Crew Neck T-Shirt is made from one of the heaviest jerseys ever produced with a weight approximately two times that of a conventional heavyweight jersey. Circular knit in Japan, the fabric has an uneven surface texture. The Crewneck T-Shirt has a modern athletic fit with binder neck ribbed collar, union special flat side seam construction and is made in Japan. 409gsm / 12.1oz per square yard 100% Cotton Japanese Fabric Made in Japan Wonder Looper have updated their sizing in March 2025. Please review the current measurements even if you have previously purchased this product in the past.