0 PPM 100 Gallon Per Day Reef 4 stage Reverse Osmosis Reef Water Filter System Ideal for Aquarium/Travel/ Apartment/ RV/ Mobile Home/Yacht item include all filters , membrane and a 1/4" RO tube Quick connector for aerator faucet(work for bathroom sink)55/64"-27 female - 1/4" pipe qiuck connecter Make perfect 0 PPM water for your aquarium purpose.