F-One introduced the ESL construction with the 2017 collection. Shape are identical with the other available construction. This series has proved to be quite popular, its pricing (cheaper than the more expensive Pro Flex series) being the main attraction but also for the rider who like to wax their board and have a more direct feel with the water. ESL stands for Essential and that the ESL series is a bull bamboo and double bamboo deck construction series, stiffer and super strong (as opposed to the Pro Flex series made of HD Foam Flex composite + heel shock absorber + deck stringer).
For 2019, F-One has added inserts to the ESL series and also, as an option, front pads for MITU and SLICE ESL. They sell separately from the board, and it’s a new product in the 2019 collection. Retail is $59. If you enjoy riding with a pad rather than with wax, then the front pad comes handy.