This is a M/L jumpsuit. It does not come with the belt. Belt is available for purchase as well. One one available. Button has some stretch. 

Additional Info

MODEL'S STATS FOR SIZING: - HEIGHT: 168 cm / 5'6''- BUST: 35" - WAIST: 27" - HIPS: 41"

MODEL IS WEARING a US M/L

SIZE INFO: True to size. In US

Small=2-5, Medium=6-8, Large=8-10.