Dwyer Instruments” Series SSL gauges have dual English/metric scales with 1 percent full-scale accuracy. The Series SSL is a four-inch, glycerin-filled gauge, designed with a 304 stainless steel housing and 316L stainless steel wetted parts for strong chemical compatibility. Gauges come standard with a 1 1/2” Tri-Clover process connection for easy installation with a tri-clamp fitting. A wide selection of ranges are available from full vacuum, compound to 300 PSI (2 MPa).