These NLL-SS & NLC-SS are used in the same applications as our regular NLL and NLC gauges with brass internals, however these offer stainless internals for food or beverage processing, petrochemical, or more harsh environments which are subject to corrosion and wider temperature ranges. They have a 304 stainless steel case, 316 stainless connection & bourdon tube, polycarbonate lens, and an upgraded silicone liquid fill (Y2024 we are doing a rolling change to inventory from previous Glycerin fill to Silicone fill - confirm actual stock). Silicone fill -40°C (-40°F) to +80°C (175°F). Liquid gauges should be perforated or "burped" when installed.