The 5 series is brand new for the Cera Nova X line, and fulfill a hardness gap between the 4 and the 6 series. Itâ€™s easier to apply than the 4 series, but provides outstanding glide properties within its temperature range, and has a great durability.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 appr. one minute. Important to have a good iron to get an efficient melting of the wax. Scraping after appr, one minute.