F6 Alpha-THRUSTER - MEDIUM-The F6 Alpha is a medium size Balanced fin with a Ride Number of 5.5. Alpha's C6 composite material is carbon and air infused making it lighter than Honeycomb. The responsive flex characteristics of C6 combine with the neutral F-Series template to create one of the most exciting new products on the market. All Alpha products are designed and manufactured exclusively in Huntington Beach, Ca USA.--CONSTRUCTION-ALPHA-Our Alpha fins are made with a special composite designed with the help of 3M. It's carbon and air infused, and it's super lightweight.