The TRAX has been the F-One best seller for years. Still is. It has always come in two constructions, Lite Tech and Carbon. This year, F-One is introducing a price point TRAX, call the ESL Series, following in the footsteps of the MITU ESL Series. ESL stands for Essential with a focus on optimizing construction process to minimize cost, and keep the shape and program as close as possible to the Lite Tech or Carbon series. Equipped with the Platinum 3 Pads/Strap, Unibox Fins and Handle. Width is quite wide so a 135 x 42cm would be the equivalent of a 137 x 42 Trax Lite Tech. When you choose a twin-tip the length is an important factor, but the width as well !