This is an instructor's cap from the Airborne Brigade. The color is navy blue. The underside of the brim is dark green, which gives it a stylish look. It's a type of hat known as a baseball cap or Apollo cap. Whether or not it has a star indicates if it's for an instructor or an assistant instructor. Because replicas are also available, I understand that it can be obtained by civilians. The size is M. The adjuster at the back of the head allows for adjustment within a range of approximately 57-59cm. This item is set to donate 5% of the sales profit to Doctors Without Borders. *Photos were taken on a desk.*