Wedge type plug gauge（Oblique ruler）Suitable for on-site measurement of depth gaps, depth apertures, and inner diameters. For example, industries such as electricity, railways, construction, bridges, transportation, welding, highways, shipbuilding, steam turbines, water turbines, large water pumps, ceramic sanitary ware, automobiles, molds, oil nozzles, and nozzles.

Oblique ruler(Slope gauge) - Suitable for on-site measurement of depth gaps. Example: The gap between ceramic sanitary ware and the ground and wall, mold gap, etc. The purpose is relatively single and can only measure gaps.