Parker 68P-8-4 Compression Fitting for Thermoplastic and Soft Metal Tubing, Poly-Tite, Tube to Pipe, Brass, Compression and Male Pipe Connector, 1/2" and 1/4": Amazon.com: Industrial & Scientific
Amazon.com: WYNNsky Tank Mini Ball Valve, 1/4''NPT Female Threads×1/4''NPT Male Threads, Shut-Off Air Compressor Accessories Fittings : Industrial & Scientific