Dorsal Thruster Surfboard Fin Box Set [Black - White] Thruster Fin Box Set - Available [Black - White] DORSAL (Futures Brand Compatible) Fin boxes(Side Boxes -3/4" deep)(Center Boxes - 1/2" deep) Available in -Singles-Tri (two 3/4" sides &amp; one 1/2" center)-Quad (two 3/4" sides &amp; two 1/2" centers)