ENJOY EXTRA COMFORT: The men's thermal onesie are made of 100% polyester. DELICATE DESIGN: Long-sleeve onesie in double-layer thermal featuring full-button placket and crew neckline with tagless label. Botton-up front to easily put on and take off. GREAT FIT: Built for athletic builds with higher armholes and lower trouser rise. Close fit along torso and connections to extremities- better movement allowed. VALUABLE GIFT: Available in various sizes so you can find just the right size that matches you. Choose from different sizes and treat yourself to the most comfortable-fitting thermal union suit today. Give this thermal union suit as a thoughtful gift for your loved one's next birthday or for Christmas. ABOUT SIZE: Please check the size information under the Last Detail image before ordering to ensure you the utmost satisfaction possible with this product.