The K6, K8 and K10 all share the same hardware platform. This means that by purchasing a K6, it is possible –as your business and your power requirements grow- to upgrade the platform’s output power. This is carried out using the Model Step-Up Card and each step costs, more or less, as the price difference between the various models. For example, one Step-Up will transform the K6 into a K8, two Step-Ups will make the K6 a K10.Of course the K8 can also be upgraded. The K2 and K3 on the other hand, are based on a smaller hardware, so it is possible to Step-Up from K2 to K3, but not from K3 to K6. Same goes for the K20, which is also based on a different hardware, making the K10 the highest possible upgrade currently available.