SMC Originals Wool 125

-Needle Size: 4 mm, US 6, UK 8
-Ball Weight: 100 gram, 3.5 oz
-Length: 125 meter, 136 yards 
-Materials: 100% Virgin Wool
-Gauge: 10 x 10 cm 22 stitches and 30 rows

For a hat you'll need 1 ball and a scarf 3 balls of yarn.