Quick Connect Reducer (1/4 Inch x 3/8) The Quick Connect Reducer (1/4 Inch x 3/8) is an RO tubing reducer fitting for adapting a 3/8" line down to 1/4" tubing. Reducer Fitting for RO and Utility Pump Lines This fitting is useful when connecting equipment or plumbing that uses different tubing sizes. It works well with Neptune Utility Pump setups or similar devices where a 3/8" line needs to transition to 1/4" RO tubing. Fitting Details Quick-connect reducer fitting. Reduces 3/8" tubing to 1/4" tubing. Designed for compatible rigid RO tubing. Useful for RO/DI plumbing, ATO setups and utility pump installations. Directions Cut both tubing ends squarely and push each tube fully into the correct side of the reducer. Pressurize slowly and check the reducer for leaks before leaving the system unattended. What's Included 1 Quick Connect Reducer - 1/4 inch x 3/8.