High Pressure Tubular Gauge Glass - Sold by the Inch

Redline striped glass makes clear liquids such as water very easy to see compared to using clear glass tubes, especially when viewing from a distance.

By positioning the redline stripe side of the glass opposite the operator’s viewing position, the redline stripe is magnified by the liquid in front of it. Thus the redline will appear very wide where liquid is present and very narrow where liquid is not present.