Needle valves are constructed to meter fluid and gases.  They are O-ring sealed to eliminate valve maintenance.  The O-ring is positioned between the actuating threads and the seat, and seals the closely fitted cylinder to give the lowest possible internal volume and protect the threads from contamination.    Available in angle and straight patterns.  Both patterns are available for panel or bracket mounting.  
V1 has a medium tipped stem (37°) to offer rapid shut off, full flow and a semi-metering function.