The World's First Fin With Four Channels • Four Channels • Rubberized Side Ribs • Anatomical Foot Pocket ABS Buckles The Avanti Quattro has set the standard for which all fins are measured. • Rubberized side ribs improve elasticity and protect the blade from cuts and abrasions • The Avanti Quattro fins feature blade stabilizers to improve stability and eliminate ankle-twisting phenomena • The anatomic foot pocket features interior ribs that improve fit, eliminate foot suction and prevent foot pocket flexing which transmits more power to the blade • The straps feature ABS (Adjustable Binding System) SIZE:S-R-XL.