What does "five-ten one-twenty" mean?

Very plausibly sizes : 5 feet 10 inches, and 120 pounds. Models are notoriously required to be tall and thin.

EDIT In metric that's around 1.78 m and 54 kg.


She is referring to a typical model's height and weight, '5 foot 10 inches tall and weighing 120 lbs'. Not sure how this converts to metric but would indicate a tall, thin person in US.