PuroTwist 4 Stage 50 GPD TFC Quick Change Water Filtration Retro Fit System. Quick change head with 50 GPD membrane, Q5605 sediment prefilter, Q-5633 GAC carbon prefilter and post filter No tank, faucet or installation kit. Uses John Guest quick connectors that are very easy to install. Works in place of the ® DuPure or ® Raine "-60" Pure Blue - ® Omnipure -60 "Q" Series systems. Converts stadard style cartridge RO systems to quick change filters for easier maintenance.