High Quality Metal Materials: The EIGNO gauge is composed of aluminum plates with anodized surface. The bolt is made of SUS304 stainless steel, machined with ultimate precision which is more corrosion-resistant. Wide-ranging Size Detection: Suitable for checking 28 mainstream models bolts and nuts, 14 metric gauges and 14 standard gauges can be carried separately for use. Encompassing Metric thread sizes from M4 x 0.7 to M14 x 2.0, and Imperial threads from # 6-32 Coat to 1/2-20 Fine. Space-Saving Design: Gauge kit (metric +standard) size 20x20x2cm (7.87x7.87x0.79 inch). The size of individual metric or standard gauges is only 20x10x2cm (7.87x3.94x0.79 inch), Weighing only 400g (0.88lb), convenient to fit into small spaces such as pockets and toolboxes. Solve Your Trouble: When faced with scattered piles of nuts and bolts, it takes only a few seconds to quickly and accurately know the dimensions of different bolts or nuts. This will save you significant time and extra costs. Meticulous Design: The pre-drilled installation hole design facilitates the fixation of the gauge on the toolbox and wall. The centimeter and inch rulers on the gauge help you quickly and accurately measure the length of bolts, screws, nuts, washers.