ARO, 12V DC, Solenoid / Spring, Solenoid Air Control Valve - 6JJ52|P251SS-012-D - Grainger
Amazon.com: 4-Way Solenoid Valve 1/4" With All Fittings (12-Volt) for Pneumatic Cylinders, Includes 1/4" push-in air fittings and speed control brass mufflers : Industrial & Scientific
U.S. Solid 1/4" Pneumatic Electric Solenoid Valve 2 Way 2 Port DC 12V, Air Water | eBay