This is a very simple watch cap pattern, written for aran weight yarn.

As a general guideline, approximately 125g of the Jaeger Shetland Aran made 2 hats, so if you have 2 balls of this yarn, you should be able to make 3 hats. Why is this important? Because, yarn is usually available in 50g balls and you will very likely need more than 1 ball for 1 hat :)