Next level combination of grip and glide with Rex Dual Compound technology: The innovative recipe of Rex's N-line grip waxes consists of both pressure-sensitive and temperature-sensitive raw materials in an optimal ratio, to achieve a perfect balance for the demands of todays World Cup racing tracks. Taking advantage of Rex N-Kinetic technology increases the glide and dirt repellency of the series. N-series grip waxes can be used as cover waxes, or just on their own. Already World Cup proven with a confirmed win with N-line waxes! The fluor-free N-line series replaces Rex's previous Pro Grip series. N21 Blue ia a wax for mid-frost conditions. N21 has fairly hard consistency, but gives you still good grip thanks to Rex Dual compound materials. Can be used as on its own, as mid layer or as a cover wax.