From the pattern:
“The technique of smocking gathers stitches together and creates a richly textured stretchy fabric, perfect for the brim band of the hat.”

Finished measurements:
Circumference at brim band 16” (41 cm) unstretched, 17” (43 cm) in length from brim edge to crown tip; will fit head circumference of 20” to 23” (50.5 to 58 cm)