"#728937: 1/4 in Quick Connect Inline Shut Off Valve. This is used to shut off feed or outlet line to system. This valve is for the Stealth RO™ system or the Small Boy™ systems as well as any other 1/4 in systems. #728939: 2 Way Splitter 1/4 in. This is a Y splitter for multiple reservoirs for the Stealth RO™ system or the Small Boy™ system as well as any other system that takes 1/4 in tubing."