The Lightning M-5 Mainsail has proven to be a total all-around performer in all sailing conditions and has been part of inventories that have helped clients win around the globe from fleet to world championships. Our custom headboard as well as computer designed clew and head patches help the M-5 maintain a smooth shape. Built out of 3.8 oz. yarn-tempered cloth, the M-5 is the ideal mainsail for the sailor who enjoys the ability to change and set your tuning to fit your individual sailing style.