This is a new made reproduction of the standard mounted style campaign hat chinstrap used by US Army and by USMC officers.  The strap is 1/2 inch wide and adjuststs for length with a buckle.  It is meant to go through the grommets on the hat brim (or through slits made by the owner on earlier style campaign hats without grommets) and around the hat cord.  This strap cannot be worn without a hat cord.  Can be worn either around the back of the head or under the chin.  I have sold over 1000 of these chinstraps to many happy customers.