New, old stock without box. Static O Ring SOR 12N-K45-N4-B1A Pressure Switch Serial Number: 020700977 Adjustable Range: 1-16 PSI Over Range: 200 PSI Proof: 400 PSI SOR pressure switches are rugged, field-mounted instruments. The pressure sensing element of the SOR pressure switch is a force-balance, piston-actuated assembly. The sensing element is sealed by a flexible diaphragm and a static o-ring. A wide selection of wetted parts materials for media compatibility and containment are available. A metal diaphragm may be welded to the pressure port for certain applications, thereby eliminating the o-ring.