( 2 Fin Set ) Futures Compatible: These side bite fins are designed to provide the maximum amount of performance when added to a single fin on 2+1 surfboards. A great all around template, these fins will provide that extra level of stability, projection, and hold you are looking for out of your setup.
However… the 3.7″ are the most often recommended size.
This 3/4″ Futures Fin Base Does Not Fit For Rear Quad
BASE: 3.63” / 92.20 mm
AREA: 10.25”² / 66.12 cm²