The Boogie Regulator goggle is designed to work on a variety of helmet configurations. The Bungee Cord/ Velcro strap option lets you attach the strap to the helmet and replaces the silicone full strap. This Bungee Cord/ Velcro strap option will come with two post mounts that clip into helmet rail mount systems. Black kit will come with black posts. Tan 499 kit will come with Tan 499 posts.