Swix Sport Cera Nova HF4BWX is a new special wax for extreme cold conditions with BW solid lubricant additive that reduces the dry friction in very cold snow. ** You will need a quality iron to apply Black Wolf ** The speed of the iron should be approx. 8-10 sec. on a skating or alpine ski. The wax can be re-heated after cooling to room temperature (10 min) for better durability. Scraping after approximately one minute. Important to have a good iron to get an efficient melting of the wax. HF04BWX can be used as a race wax alone or as a base for Cera F cold powder, such as FC04X. Temperature range from -12C to -32C (10F to -25F). Recommended iron temp: 155C (311F).