What are the child requirements for forward-facing use with the internal harness?

For forward-facing with harness use, children must weigh 10 - 29.5 kg (22 - 65 lbs), have a height of 71 - 124 cm (28 - 49 in.), have their ear tops at or below the top of the child restraint headrest, and be at least 2 years old. Once your child exceeds any of these size requirements and is at least 4 years old, you must discontinue use of the internal harness and begin using booster mode. (Page 38)