This romper buttons at the top front and on each side.

You will need 8 buttons - Sirdar used their Button # B5600-0097

Finished measurements:
Chest circumference: 16.5( 18, 19.25, 20.5, 21.75, 21.75)“ 42( 46, 49, 52, 55, 55) cm
Finished length: 17.25(18, 18.5, 19, 19.75, 20.5)” 44(46, 47, 48, 50, 52) cm

Yarn used:
Sirdar snuggly Baby Bamboo DK
Shade 099 Nellie - 3(3, 3, 4, 4, 4) balls