NUMBER OF CHANNELS: For home use, we have the single-channel CS1 series of advanced generators: (CS1-12) for 15 different metals, and CS1-1 for Silver only. We also have multichannel CS2, CS4, and CS6 series for making 2, 4, or 6 simultaneous batches, each channel having the capability of making separate 5-liter batches. Multiple channels: I am now recommending that customers not buy our multiple 4, 5, and 6 channel generators and instead buy two or more CS2-12 two-channel models. This is our most popular model and the price is about the same. In this way, it is better to have redundancy in case of problems and the unlikely need to send a unit back to us for repair. In this way, you would have one or more backup two-channel units.