It is the 12 levels of the G5 mode. That are the ones meant by "available" lumen levels. You can just assign these to any level (L1, L2, M1....) you like. So for the SC5w Mk II for example the data of the lumen levels is 0.09, 0.33, 1.1, 3.2, 8.6, 21, 46, 92, 166, 274, 407 and 550 lumen.