They are specific to the CCR3 to my experience. The shaver will charge up without them, and even a specific shoe charger to charge it up. Bought my original Braun on a flight to Brisbane. Wonderful in the heat, but good hear to avoid razor rash without unguents.
Hi there Mr W, yes it does clean series 3 I have just bought a series 3 390cc shaver and wanted some spare cartridges long before the first one ran out. It seems to be doing very well and leaves a nice lemon smell after.