Waterdrop G3P800 Reverse Osmosis System, 800 GPD Fast Flow, NSF/ANSI 42 & 53 & 58 & 372 Certified, 3:1 Pure to Drain, Tankless Under Sink RO Water Filter System, LED Purifier, Smart FaucetDrilling 2 holes for installation. One for RO faucet and the other for drain pipe connection.【NSF/ANSI standard 42 & 53 & 58 & 372 certified】This tankless reverse osmosis system is certified by IAPMO R&T against NSF/ANSI 58 for reduction of TDS. Also it has been tested and certified against NSF 42 & 53 to reduce chlorine, bad taste, odor and so on. Besides, the system is certified by NSF/ANSI 372 for lead-free materials.【800 GPD high capacity, 3:1 pure to drain ratio】The Waterdrop G3P800 reverse osmosis system offers a higher water capacity (800 gallons per day), thereby meeting demands of a big family for pure water. Furthermore, by high water flow, it filters one cup of water in just 6s. By an advanced water dispensing technology, this tankless RO water filter system produces just a cup of wastewater for every three cups of filtered water produced.【10-Stage filtration】Tested by official third-party laboratory (SGS), through 10-stage filtration, G3P800 can effectively reduce PFAS, fluoride, heavy metals like lead, chromium, iron, salts like nitrate and chloride as well as large particles and radioactive substances such as radium.