Brand new for Swix as part of their renewed F4 line up, The F4 Warm Rub-On Wax focuses on environmentally friendly raw materials. Designed as a quick and easy solution F4 Warm Wax should be applied by rubbing the wax on and then corking it in to melt the wax, best applied on a warm ski indoors. The F4 Warm Rub-On Wax lasts longer than its liquid counterpart. For conditions -4 ˚C and warmer.