You can open the Jingdong or Suning E-shopping, the 20L, 23L and 25L cavity size parameters to do a comparison, calculated volume results almost not much difference, the volume is basically in the 21-22L or so,

And he will be in the inconspicuous place to write, by the production of the 25L platform, the actual volume space of 22.7 liters, if you mind the person please be careful to buy. 25L is just a gimmick, the actual use of the cavity space and 23L almost almost how much. If you pay attention to cost-effective, choose 23L inverter first-class energy efficiency, than 25L fixed frequency second-class energy efficiency to be appropriate. Energy saving is also cheap, if you want to use the years longer on the choice of 20L mechanical knob, electronic, after all, not as long as the life of the mechanical knob, solid and durable. The above is only a personal recommendation, do not have to meet the actual, just a reference.