Marquest L Series Needle Valves with Serrated Barb Tip provide precise flow control with fine adjustment of corrosive and high purity fluids. Standard Inlet sizes are 1/4", 3/8", & 1/2" Female NPT with a Serrated Barb Tip that accepts 1/4" - 1/2" ID Tubing. The L Series PTFE On/Off seal provides the ultimate in On/Off Product Cycle Life with an unlimited life warranty. Materials available: PVC, Natural Polypropylene, & PVDF.