Checkline J-300 [J-300-A] Dial Thickness Gauge, 10mm Range, Depth Of Jaw 300 mm, Feeler A (30 mm) For Rubber, Felt, Soft Materials, Non Wovens. Resolution: 0.01 mm, Measuring range: 10 mm or 30 mm, Depth of jaw: 300 mm. Thickness gauge to determine the thickness of leather, textiles, cardboard, felt, rubber, sheet metal, foil, plywood, plastic, foam and more.