Well suited for distinguishing between similar inch and metric threads. The individual gauges rotate freely on the wire cable for fast Verification. Includes: (13) inch sizes: #6-32, #8-32, #10-32, #10-24, 1/4"-28, 1/4"-20, 5/16"-18, 3/8"-24, 3/8"-16, 7/16"-20, 7/16"-14, 1/2"-20 & 1/2"-13 ·(12) metric sizes: 4mm x 0.7, 5mm x 0.8, 6mm x 1.0, 7mm x 1.0, 8mm x 1.0, 8mm x 1.25, 10mm x 1.0, 10mm x 1.25, 10mm x 1.5, 12mm x 1.25, 12mm x 1.5 & 12mm x 1.75.