1970s Rainbow Square Patchwork Sweater Vest, Size S/M

Description - Cute patchwork sweater vest from the 70s. It buttons up the front with little gold buttons. 

Details

Brand - Unknown, only a content label is present

Content - 100% Acrylic

Size - S-M

Shoulders - 12.5" across

Chest - 17.25" pit to pit, stretches to 18.5"

Length - 19.5"

Condition - there is a green mark on the back. I'm not sure what this is.