B14 MAINSAIL The M07B works equally well with either the carbon masts or the older aluminium masts. Careful attention has been paid to luff curve and in particular with regard to the depth in the head.The sail works in harmony with the whole of the mast, not just the top section to produce a sail that will power up in medium winds and 'flick off' automatically when overpowered. The code M07B is a radial design with a full head. The sail is made from ODL04 and comes complete with full length battens and windows.