Hmm. We would be hard pressed to recommend that unit. If you are going to buy it, at a minimum, unclip the horizontal DI stage and orient it vertically with bottom up flow. Given the broken english on that website, be prepared for more of the same in the instructions you are likely to receive.
The GAC filter has a capacity of 1500 gallons. Because that includes the water that will go down the waste line, be prepared to change it after you make less than 300 gallons of purified water. To be kind, it is very unusual for that GAC filter to be used before an RO membrane. It is more typically used as a filter between an RO pressure tank and a faucet.
I encourage you to do some homework before you buy!
Russ