The Mac 33 series is a direct solenoid operated 3-way - 8mm - poppet valve. A direct operated 3-way of this size with such high flow is unique to MAC due to patented design innovations. It features an oval armature in the solenoid, a balanced poppet and powerful return spring. These features translate into high shifting forces, fast consistent response times, high flow in a small package and long life. For information regarding certifications (such as UL, CSA, RoHS, and CE) please visit the Get Support pages on our website.