Muscleback design offers flexibility and freedom of movement, so you can swim in comfort 100% Chlorine resistance build, for long-lasting performance Quick dry fabric dries faster after your swim workout Take on your training wearing the funky Dive Thinstrap Muscleback from Speedo's much-loved Essentials range. Featuring an eye-catching dual-tone colour block splice with aprinted panel, the muscleback design with thin straps offers flexibility and freedom of movement.