The Loos economy tension gauge takes the guesswork out of cable tension adjustment. It's especially designed for accurate, repeatable tuning of a sailboat's standing rigging. - Manufactured of rugged anodized aluminum, the gauge is corrosion -resistant and will provide years of service. Please read the detailed operation instructions that accompany the gauges carefully to ensure complete accuracy. Each Model includes a Loos & Company Cable Diameter Gauge, LOOS part no. GA-4