In the picture here you can see one of the home brew kit options (20L Plastic Keg + 5L) connected with some of the included gear to the optional 35L fermenter in one very useful configuration.
If you brew with the 35L Snub Nose (or any other pressure fermenter) with a spunding valve attached (also included in this home brew kit) during fermentation you end up with carbonated beer just using the CO2 produced while brewing. If you connect the fermenter to the 2 kegs (again all equipment is included) during brewing the CO2 produced will also flush out your kegs and pressurise them ready to be filled.
Once brewing is complete you simply increase the pressure on the regulator slightly to transfer your finished beer to the kegs, under pressure with no loss of carbonation or chance of contact with air.
You can also just walk away and let it do it's thing as with this setup the large keg will fill first, once it is full the small keg will begin filling and once either the small keg is also full or the fermenter has emptied the red ball will float in the sight glass and stop all transfers.
If you don't use a pressure capable fermenter yet, don't worry you can still easily transfer from your bucket to the kegs with this kit and then use the regulator to carbonate both kegs simultaneously.