From True Ames

( 2 Fin Set ) Futures Compatible – Solid Fiberglass: 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.

Our side bites are offered in six different sizes, so you can find a set to meet any style of board or any sort of need!

However… the 3.7″ are our most recommended size for 2+1’s.

This 3/4″ Fin Base Does Not Fit For Rear Quad

• HEIGHT: 3.70 / 93 mm
• BASE: 3.63 / 92.20 mm
• AREA: 10.25 / 66.12 cm