The Solla is made of a thermoplastic elastomer with a mix of hard and soft materials in the blade, the foot pocket and the side rails. The very noticeable stiff-to-flexible gradient in the blade gave the Solla good drive without taxing leg muscles. Most divers also liked the anatomic heel strap, which has an arched section in the middle (and a generous finger slot that earned very good scores for donning and doffing), although a couple of divers with thin boots found the strap design a little tight on their heels. The Solla’s modest size also made it quite maneuverable. A very capable open-heel fin that does everything well — and at a friendly price — the Tusa Solla is our Best Buy.