Pattern includes instructions to knit this as a sleeveless waistcoat vest with pompom tie (separate Ravelry entry here).

Sizes: to fit chest / actual measurements
2-3 yrs (chest size 22”/56cm) / (24”/61cm)
4-5 yrs (chest size 24”/61cm) / (25.5”/65cm)
6-7 yrs (chest size 26”/66cm) / (28”/71cm)
8-9 yrs (chest size 28”/71cm) / (29.5”/75cm)
10-11 yrs (chest size 30”/76cm) / (32”/81cm)
12-13 yrs (chest size 32”/81cm) / (33.5”/85cm)

Yarn Requirements: Aran weight, 100g balls
2 (3, 3, 3, 4, 4) balls

Also Needed:
4 (4, 4, 5, 5, 5) buttons

Sirdar website link: Supersoft Aran 2300