X-flex super stretch arm panels for flexibility & freedom of movement; D-flex lower body panels for durability; Non-petroleum based neoprene; Blindstitch seams for 100% water seal, flexibility and warmth; G Flex tape re-inforced crotch seams; Seam free seat for maximum stretch; Tech-Neck single layer seal; Dura Skin chest and back print to prevent wind chill; Titanium 2 lined neoprene reflects the heat back in; Powertex knees for flexibility & durability; Ankle adjusters for easy entry; YKK zip with metal puller.