The SoClean and the SoClean 2 are both excellent CPAP sanitizing devices that are very similar. The SoClean disinfecting unit is made for home use with a plugin base and a timer to help you stay on schedule with a cleaning routine.
The SoClean 2 utilizes the same awesome disinfecting power of Ozone, but in a way that makes it simpler to travel. The SoClean 2 is more compact and easier to bring with you as it has no chord, and does not need an electrical socket. However, this unit does not have an option for setting up a programmable routine.
As far as cleaning your CPAP machine, both units work very similarly. They both connect to your hose and use a built-in chamber that concentrates the ozone to germ eradicating levels. The most significant difference is one is a programmable unit to be used at home while the other is more travel-friendly, making it easier to take your CPAP equipment on the go.