Gauge: 24 sts & 28 rows in k4 p2 rib pattern to 10cm
64 sts or 72 sts cable mix = about 25cm wide

This is called a “slipover” and it’s a very long tunic vest with a thick roll turtleneck. Hence the yardage requirement. Total length from turtleneck to bottom = approx 78cm / 30 inches.