This set is made of a ribbed knit heavy weight material. Soft and oversized. Half zip neck, slightly cropped, and side slits on the top. The bottoms are flared at the bottom, has side pockets, and an adjustable drawstring waist. Super cozy set! 
I’m 5’4 130 lbs in a size small. If you’re between sizes, you could size down. 
37% Nylon 36% Polyester 25% Rayon 2% Spandex