This set is made out of matching yarn that changes colors from white to yellow to gray.  The hat has a furry pom pom attached by a snap to the top and measures 21" around and stretches to 26".  The length is 8".  The length and can be adjusted by rolling up the bottom of the hat or pulling down the top of the hat to form a slouch off the back of the head.  
The scarf is 43" long and has a keyhole opening where one end of the scarf is pulled through the opening of the other end (see picture). 
The yarn is acrylic for easy laundering.