From the pattern:
“Lacy navy square have flower petal centers, crisp white edges in half double crochet for this pretty polo shirt style. Sleeves and collar are in solid half double crochet.”

Body Bust Size: 31-1/2” - 32-1/2” (34” - 36”)
Blocked Bust Size: 35” (37-1/2”)

GAUGE: Each A Square = 3-1/2” (3-3/4”) square.
4 hdc = 1” (size G hook); 7 hdc = 2” (size H hook).

Both sizes are made the same, just the hook size and gauge are different.