Medium-R series is standard double stage reverse osmosis system. With 2 stage pump, 2 stage RO membrane and buffer tank, system achieves stable water quality, little drain, and low running cost. Compared with single stage RO system, the quality of RO water is better, and the running cost is lower for less consumables replacement. Moreover, compared with simple 2nd stage RO system (1 pump, 2 RO membrane, without buffer tank), its system design is more rational, and the RO quality is more stable. Even though with the worse source water, the 2nd stage RO water’s conductivity also can stay 1-5µs/cm. Medium-RRO series is 2nd stage RO water system, with LCD controlling system, 3 way water quality sensor, cartridge replacing alarm, timing and quality dispensing, stainless steel shell, built-in 2 set tanks (buffer tank and pressure tank). Its output ranges from 30 to 90 liters/hour. And the 2nd stage RO water’s conductivity can stay 1-5µs/cm, suitable for glassware washing and general grade experiments.