FCS thruster and quad sets are categorized by size. Each size category has an optimum weight range that can be used as a guide when choosing a fin:


All FCS thruster, quad and quad rear fins come with fin ratings. These fin ratings provide the drive, pivot and hold characteristics of each individual fin set and are based on elements such as area, base length, sweep, depth, material and template.


FCS provides these fin ratings as a guide to individual fin performance. They can also be used as a reference when choosing a fin for specific performance requirements. 


Fins are rated relative only to the fins within each size category and are not comparable across other sizes. For example, the drive rating on a medium fin can only be compared to the drive rating on other medium fins.