The Rolling Wheel Wet Film Thickness Gauge has long been the standard for measuring wet film thickness in the coatings industry. （U.S.Patent No.3, 128,558）.

The gauge consists of an eccentric inner wheel, supported by two large outer concentric wheel. At a specific point, the inner wheel touches and picks up wet film when the gauge is rolled on the coated surface. The critical clearance may be read on a rotating scale.

Both the body of the gauge and the centre holder are made of high-grade stainless stee. The scale value are casted on 1 side.

Biuged offer three basic models in various ranges. All models have an accuracy of 2.5µm（±0.0001 in） or 2.5% full scale, whichever is greater.