Futures Fins Hayden Shapes HS2 Generation Tri Fin Set MediumHS2 Generation Tri Fin Set Medium The next level in speed generating fins is here with the all new Generation Series. These fins will provide all the speed you need while maintaining an element of control. Sitting one notch below the Blackstix on our Ride Number scale, all Generation Series fins hold Ride Numbers between 9 to 7, for those of you looking for a bit more stability & drive than Blackstix. Ride Number 8. 3 SPEED GENERATING DIMENSIONS SIZE