The nylon liquid level gauges have adjustable centerlines to accommodate centerline distances up to ¼” longer or shorter than the specified measurement, for total adjustability of ½”. This range of adjustability compensates for variances that can occur during the production of plastic tanks. It is also used in field installations where the distance between mounting holes may be less precise than in a controlled setting. The adjustment can be made by hand, facilitating simple installation. The gauges are used to view liquid levels in hydraulic reservoirs, tanks, large steel mill pumps, gearboxes, bearing housings, hydraulic equipment, crankcases, transformers, and machinery oil reservoirs. Center measurements range from 6″ to 36″.