A compact reverse osmosis (RO) tube insert that controls drain flow and restores proper system performance. Designed for quick installation with standard 1/4' quickconnect fittings, this restrictor insert is available in five restriction sizes—150, 300, 450, 600 and 1000 cc—so you can match the restrictor to your membrane and desired wastetoproduct water ratio. Key benefits Restores RO performance: Replaces worn or incorrect restrictors to maintain membrane backpressure and rejection rates. Simple, fast installation: Pushfit 1/4' quickconnect compatibility lets you install the insert without special tools or fittings. Match your system: Multiple cc sizes let you choose the correct flow restriction for undersink units, countertop systems or compact commercial RO setups. Reduces downtime: Small, inexpensive replacement that avoids extensive plumbing changes. What it does (functionality) Acts as an inline flow restrictor inserted into 1/4' tubing on the RO drain line. Controls the flow of concentrate/waste water to maintain the correct pressure across the RO membrane. Helps the system produce consistent purified water while preventing excessive wastewater. Key attributes Compatibility: Designed for use with standard 1/4' quickconnect tubing and fittings common on residential and lightcommercial RO systems. Sizes available: 150 cc, 300 cc, 450 cc, 600 cc, 1000 cc options to suit different membrane capacities and desired flow ratios. Form factor: Inline tube insert for easy placement inside 1/4' tubing. Material and durability: Constructed for routine RO system use; designed to withstand typical potable water conditions and continuous operation. Performance: Provides stable flow restriction appropriate to the selected cc rating to help maintain membrane pressure and system efficiency. Installation notes Cut the 1/4' tubing where the restrictor is needed, push the tubing ends onto the quickconnect fittings, and ensure a secure seat. No soldering or special adapters required when your system uses 1/4' pushfit connections. quickly when performance drops or when switching to a different restrictor size to rebalance system output. Common use cases Undersink residential RO systems: a failed or inappropriate restrictor to restore proper water production and waste ratio. System tuning after membrane or filter changes: Swap to a different cc size to match a membrane or to adjust purified water output. Small commercial or pointofuse RO units: Maintain consistent performance in labs, small offices, cafes, or vending equipment that use 1/4' tubing. Why customers choose this restrictor insert Practical and costeffective way to maintain or tune RO systems without plumbing changes. Multiple size options make it easy to fit a wide range of RO setups using standard 1/4' quickconnect tubing. Straightforward inline design minimizes installation time and error. Package tip Verify your system's tubing size (1/4') and the desired restriction rating (150, 300, 450, 600, or 1000 cc) before ordering to ensure correct fit and performance.