Fins, masks and snorkels Full foot fins C4 Mustang Ht50 30 Carbon. The new HT 50 Hypertech series is specially designed for high competition. The new carbon pre-impegnated BIGSQUARE have higher performance in new models of shovels. This new carbon (High Transmition) has been designed exclusively by and for C4. This new pre-impegnated carbon is characterized by a more elastic and strong response. The new HT Series is directed to athlete High competition very experienced. More compact design, low ripple carbon and three times more elastic.